The interpretation timeline
Luke 18:13 Douay-Rheims

And the publican, standing afar off, would not so much as lift up his eyes towards heaven; but struck his breast, saying: O god, be merciful to me a sinner.

A.D. 379 – 1871 7 witnesses

Patristic

before A.D. 750
379
A.D.
Basil of Caesarea Patristic
c. A.D. 330–379
“(in Esai 2. 12.) In like manner it is possible to be honourably elated when your thoughts indeed are not lowly, but your mind by greatness of soul is lifted up towards virtue. This loftiness of mind is seen in a cheerfulness amidst sorrow; or a kind of noble dauntlessness in trouble; a contempt of earthly things, and a conversation in heaven. And this loftiness of mind seems to differ from that elevation which is engendered of pride, just as the stoutness of a well-regulated body differs from the swelling of the flesh which proceeds from dropsy.”
Source

Scholastic

c. 1100 – 1500
1107
A.D.
c. 1055–1107
“Although reported to have stood, the Publican yet differed from the Pharisee, both in his manner and his words, as well as in his having a contrite heart. For he feared to lift up his eyes to heaven, thinking unworthy of the heavenly vision those which had loved to gaze upon and wander after earthly things. He also smote his breast, striking it as it were because of the evil thoughts, and moreover rousing it as if asleep. And thus he sought only that God would be reconciled to him, as it follows, saying, God, be merciful.”
Source

Reformation

c. 1500 – 1650
1637
A.D.
1567–1637
“And the publican , standing afar off. The publican did not resent the insult offered by the Pharisee, nay, he admitted it, confessed it, and sought pardon for it with patience. He was therefore justified before the Pharisee. S. Chrysostom, in his Homily on David and Saul, says, “ The publican accepted the disgrace and washed it out. He acknowledged his sins, and laid them down. This accusation was to be his remission, and his enemy was changed involuntarily into his benefactor. How many labours ought that publican to have undergone, fasting, sleeping on the ground, watching, bestowing his goods on the poor, sitting long in sackcloth and ashes, that so he might lay aside his sins? But when he did none of these things, by a mere word he was rid of all his sin ; and the insults and reproaches of the Pharisee, which seemed to overwhelm him with contumely, bought him a crown of righteousness, and that without toil, without labour, and without long delay.” Standing afar off. Afar from the altar and the holy place, for he Digitized by Google 446 thought himself unworthy of these from his sins. He was not so very far off though, but the Pharisee was able to point to him, and he to hear the Pharisee. He would not lift up so much as his eyes unto heaven. He dared not, from modesty, humility, and reverence. He would not so much as lift his eyes, as if thinking himself unworthy to look to that heaven which was the abode of the glorious God, who was offended at sins. Wherefore with eyes cast down to the ground, he humbled himself. So S. Cyril in the Catena . S. Theophylact gives the cause of his thinking himself unworthy of the heavenly vision ; and S. Augustine : “ That he might be looked upon by God, he looked not upon himself. He dared not look up. Conscience weighed him down. Hope lifted him up. Again he showed by his posture that he had sinned against the Heavenly Host, that is against the Angels whose inspirations he had resisted ; against the Saints, whose prayers he had made of no avail ; against God Himself, whose commandments he had broken.” But he smote on his breast His breast, in which was his heart, that is his will, which is its own cause and origin of all sins. “ He struck and beat it,” says Euthymius, “as if to exact punishment from it : and to show that because of it he was worthy himself of stripes.” The beating of the breast is a sign of penitence and a contrite heart. Hence this was formerly the act of one who confessed and was penitent, and it is so stilL To beat the offending breast is both an ancient and modern custom of Christians. S. Augustine in his 8th Sermon “ On the Words of the Lord according to S. Matt,” says, “ At this ‘ Confiteor ’ you beat your breasts. What is this but to confess what is lying hid in them, and by a visible blow to chastise an invisible sin ? Why do you do this, but that you hear * Confiteor tibi Pater.* Therefore our accusation of ourselves in our confession is the praising of God. For we confess ourselves to be sinners, but God to be without sin, holy and good. We therefore ask pardon of Him. The Pharisee, from his proud and unreal prayer, was the more defiled with sin. The oublican was more righteous than the Pharisee, not directly and simply, but indirectly Digitized by Google PRIDE REJECTED, HUMILITY FINDS GRACE. 447 and negatively ; for indeed he was righteous, but the Pharisee was unrighteous, and he returned to his house even more so than he came out” “For,” says Euthymius, “he who so condemned himself was justified by God ; ” and S. Paulinus (Eph. Iviii.), “ What righteousness built up, that pride pulled down. The publican, from a contrite heart, was accepted as an accuser of himself, and obtained pardon from his confession of sins, from the degree of his humility; that holy Pharisee (holy as the Jews are holy) bearing away the pack-load of his sins from his boast of holiness.” S. Bernard ( serm iii. de Annunc. ): “The Pharisee returned empty because he pretended to be full The publican, who emptied himself, and took pains to show that he was an empty vessel, carried away the greater grace.” “ Humility,” says S. Chrysostom, “ brought the thief into Paradise before the Apostles. But if humility has such power when close upon the offence, what can it not do when united to righteousness ? And if pride, united to righteousness, can depress, what will it do when united to sin ? ” “ Better are sins with humility than innocence with pride,” says Optatus. ( Cont Donat. B. il)”
Source

Post-Reformation

c. 1650 – 1900
1771
A.D.
John Gill Reformed
1697–1771
“And the publican standing afar off,.... Not at the outermost porch, or at the door: for "a man might not fix his place at the door of the synagogue, but, "he must go afar off", the space of two doors, and then pray (r);'' it may be in the court of the Gentiles, when the Pharisee was in the court of the Israelites; at least he was afar off from him: and indeed, those who came to humble themselves before the Lord, and confess their sins, were obliged to stand at the distance of four cubits one from another, that one might not hear the prayers and confessions of the other (s): and it might be, that this poor man might stand at a greater distance than was required, that he might not displease the Pharisee, who, he knew, would resent it, should he stand near him; or rather this was done, to testify the sense he had of his state and condition, and of his unworthiness; as that he was afar off from God, and unworthy to draw nigh unto him, and deserved to be kept at a distance from him for ever. So it is said (t) of the Israelites, that they trembled at Mount Sinai, and "stood afar off", , "to show their humility": and under a work of the law, and under such a like dispensation was this publican; and therefore would not so much as lift up his eyes unto heaven: and which, as it was an humble posture he stood in, agrees with the rules the Jews give (u); "the order (or posture) of the body, how is it? when a man stands in prayer he ought to set his feet one by the side of the other, and fix his eyes, "below", as if he looked to the earth; and his heart must be open above, as if he stood in the heavens; and lay his hands upon his heart, putting the right hand over the left; and must stand as a servant before his master, with trembling, and fear, and dread, and may not put his hands upon his loins.'' And agreeably to this, it is elsewhere (w) said, "he that prays, ought to fix his eyes below, and his heart above.'' And the Jews used to look downward, or shut their eyes, for the sake of attention in prayer; and it was even forbidden them to open their eyes to look upon the wall (x). This showed in the publican, that the guilt of his sins lay heavy on him; that he could not look up; that shame filled him with blushing; that sorrow caused his countenance to fall; and that fear of divine wrath, and displeasure, possessed him; and that he looked upon himself as unworthy of the smiles of heaven, but smote upon his breast: pointing at the fountain of his sin; expressing by this action, his sorrow, and repentance for it; and an aversion and abhorrence of himself on account of it, joined with indignation and revenge; and he did this to arouse and stir up all the powers and faculties of his soul, to call upon God. The Persic version renders it, "he fell on his knees, and beat the earth with his head"; taking a sort of revenge on himself for sin: saying, God be merciful to me a sinner. This is his prayer; a short, but a very full one, and greatly different from that of the Pharisee: in which is a confession that he was a sinner; a sinner in Adam, who had derived a sinful nature from him, being conceived and born in sin; and a sinner by practice, having committed many actual transgressions, attended with aggravating circumstances; a guilty and filthy sinner, a notorious one, deserving of the wrath of God, and the lowest hell: he speaks of himself, as if he was the only sinner in the world; at least, as if there was none like him: and there is in this prayer also a petition; and the object it is put up to, is "God", against whom he had sinned; with whom there is mercy and forgiveness; and who only can forgive sin; and who has promised that he will: and has proclaimed his name, a God, pardoning iniquity, transgression, and sin; and has given instances of his forgiving grace and mercy; and therefore the publican was right in addressing him by confession: the petition he makes to him is, to be "merciful", or "propitious" to him; that is, to show mercy to him, through the propitiary sacrifice of the Messiah, which was typified by the sacrifices under the law: the first thing a sensible sinner wants, is an application of pardoning grace and mercy; and forgiveness springs from mercy; and because the mercy of God is free and abundant, therefore pardon is so: but this is not to be expected from an absolute God, or God out of Christ. God is only propitious in Christ: hence it may be observed, that God pardons none but those to whom he is propitious in his Son; and that he forgives sin upon the foot of a reconciliation, and satisfaction made to his law, and justice, and so pardon is an act of justice, as well as of mercy; and that there is no pardoning mercy but through Christ. The Arabic version renders it, "spare me, because I am a sinner"; see Psa 25:11. (r) Piske Harosh Beracot, c. 1. art. 7. Vid. T. Hieros. Beracot, fol. 9. 1. (s) Jarchi & Bartenora in Pirke Abot. c. 5. sect. 5. (t) Tzeror Hammor, fol. 80. 1. (u) Maimon. Hilch. Tephilla, c. 5. sect. 4. & Moses Kotsensis Mitzvot Tora, pr. affirm. 19. (w) T. Bab. Yebamot, fol. 105. 2. (x) Tzeror Hammor, fol. 25. 3.”
Source
1832
A.D.
Adam Clarke Methodist
1762–1832
“The publican, standing afar off - Not because he was a heathen, and dared not approach the holy place; (for it is likely he was a Jew); but because he was a true penitent, and felt himself utterly unworthy to appear before God. Would not lift up - his eyes - Holding down the head, with the eyes fixed upon the earth, was, 1. A sign of deep distress. 2. Of a consciousness and confession of guilt. And, 3. It was the very posture that the Jewish rabbins required in those who prayed to God. See Ezr 9:6; and Mishna, in Berachoth, chap. v.; and Kypke's note here. So the Pharisee appears to have forgotten one of his own precepts. But smote upon his breast - Smiting the breast was a token of excessive grief, commonly practised in all nations. It seems to intimate a desire, in the penitent, to punish that heart through the evil propensities of which the sin deplored had been committed. It is still used among the Roman Catholics in their general confessions. God be merciful to me - Ἱλασθητι μοι - Be propitious toward me through sacrifice - or, let an atonement be made for me. I am a sinner, and cannot be saved but in this way. The Greek word ἱλασκω, or ἱλασκομαι, often signifies to make expiation for sin; and is used by the Septuagint, Psa 65:4; Psa 78:38; Psa 79:9, for כפר kipper, he made an atonement. So ἱλασμος a propitiation, is used by the same, for חטאה chataah, a sacrifice for sin, Eze 44:27; and ἱλαστηριον, the mercy seat, is, in the above version, the translation of כפרת kapporeth, the lid of the ark of the covenant, on and before which the blood of the expiatory victim was sprinkled, on the great day of atonement. The verb is used in exactly the same sense by the best Greek writers. The following from Herodotus, lib. i. p. 19, edit. Gale, is full in point. Θυσιῃσι μεγαλῃσι τον εν Δελφοισι θεον ἹΛΑΣΚΕΤΟ, Croesus appeased, or made an atonement to, the Delphic god by immense sacrifices. We see then, at once, the reason why our blessed Lord said that the tax-gatherer went down to his house justified rather than the other: - he sought for mercy through an atonement for sin, which was the only way in which God had from the beginning purposed to save sinners. As the Pharisee depended on his doing no harm, and observing the ordinances of religion for his acceptance with God, according to the economy of grace and justice, he must be rejected: for as all had sinned and come short of the glory of God, and no man could make an atonement for his sins, so he who did not take refuge in that which God's mercy had provided must be excluded from the kingdom of heaven. This was no new doctrine: it was the doctrine publicly and solemnly preached by every sacrifice offered under the Jewish law. Without shedding of blood there is no remission, was the loud and constant cry of the whole Mosaic economy. From this we may see what it is to have a righteousness superior to that of the scribes and Pharisees. We must humble ourselves before God, which they did not: we must take refuge in the blood of the cross, which they would not; and be meek and humble of heart, which they were not. Many suppose that the Pharisees thought they could acquire righteousness of themselves, independently of God, and that they did not depend on him for grace or power: but let us not make them worse than they were - for this is disclaimed by the Pharisee in the text, who attributes all the good he had to God: O God, I thank thee, that I am not as others - it is thou who hast made me to differ. But this was not sufficient: restraining grace must not be put in the place of the great atonement. Guilt he had contracted - and this guilt must be blotted out; and that there was no way of doing this, but through an atonement, the whole Jewish law declared. See the note on Mat 5:20.”
Source
1863
A.D.
1871
A.D.
1871
“standing afar off--as unworthy to draw near; but that was the way to get near (Psa 34:18; Isa 57:15). would not lift up--blushing and ashamed to do so (Ezr 9:6). smote, &c.--kept smiting; for anguish (Luk 23:48), and self-reproach (Jer 31:19). be merciful--"be propitiated," a very unusual word in such a sense, only once else used in the New Testament, in the sense of "making reconciliation" by sacrifice (Heb 2:17). There may therefore, be some allusion to this here, though not likely. a sinner--literally, "the sinner"; that is, "If ever there was one, I am he."”
Source
Modern · 1953 →

The in-app commentary runs from the Fathers to the early-modern record, then stops — that's where the public-domain sources end, not where the reading does. For the modern reading, follow the sources directly.