The interpretation timeline
Luke 6:39 Douay-Rheims

And he spoke also to them a similitude: Can the blind lead the blind? do they not both fall into the ditch?

A.D. 379 – 1871 8 witnesses 10 excerpts

Patristic

before A.D. 750
379
A.D.
Basil of Caesarea Patristic
c. A.D. 330–379
“(Hom. 9, in Hexameron.) In truth, self knowledge seems the most important of all. For not only the eye, looking at outward things, fails to exercise its sight upon itself, but our understanding also, though very quick in apprehending the sin of another, is slow to perceive its own defects.”
430
A.D.
Augustine of Hippo Patristic
A.D. 354–430
“(de Qu. Ev. l. ii. q. 9.) Or, He has added the words, Can the blind, lead the blind, in order that they might not expect to receive from the Levites that measure of which He says, They shall give into thy bosom, because they gave tithes to them. And these He calls blind, because they received not the Gospel, that the people might the rather now begin to hope for that reward through the disciples of the Lord, whom wishing to point out as His imitators, He added, The disciple is not above his master.”
Source
444
A.D.
A.D. 376–444
“The Lord added to what had gone before a very necessary parable, as it is said, And he spake a parable to them, for His disciples were the future teachers of the world, and it therefore became them to know the way of a virtuous life, having their minds illuminated as it were by a divine brightness, that they should not be blind leaders of the blind. And then he adds, Can the blind lead the blind? But if any should chance to attain unto an equal degree of virtue with their teachers, let them stand in the measure of their teachers, and follow their footsteps. Hence it follows, The disciple is not above his master. Hence also Paul says, Be ye also followers of me, as I am of Christ (1 Cor. 1:11.). Since Christ therefore judged not, why judgest thou? for He came not to judge the world, but to shew mercy.”
Source
“As if He said, How can he who is guilty of grievous sins, (which He calls the beam,) condemn him who has sinned only slightly, or even in some cases not at all? For this the mote signifies.”
“That is to say, first shew thyself clean from great sins, and then afterwards shalt thou give counsel to thy neighbour, who is guilty only of slight sins.”
735
A.D.
Bede the Venerable Patristic
c. A.D. 672–735
“Or the sense of this sentence depends upon the former, in which we are enjoined to give alms, and forgive injuries. If, says He, anger has blinded thee against the violent, and avarice against the grasping, how canst thou with thy corrupt heart cure his corruption? If even thy Master Christ, who as God might revenge His injuries, chose rather by patience to render His persecutors more merciful, it is surely binding on His disciples, who are but men, to follow the same rule of perfection.”
Source

Scholastic

c. 1100 – 1500
1107
A.D.
c. 1055–1107
“Or else, If thou judgest another, and in the very same way sinnest thyself, art not thou like to the blind leading the blind? For how canst thou lead him to good when thou also thyself committest sin? For the disciple is not above his master. If therefore thou sinnest, who thinkest thyself a master and guide, where will he be who is taught and led by thee? For he will be the perfect disciple who is as his master.”
Source

Post-Reformation

c. 1650 – 1900
1771
A.D.
John Gill Reformed
1697–1771
“The disciple is not above his master,.... Or "more excellent", as the Syriac, Arabic, and Persic versions render it; that is, in learning and knowledge; if the master is ignorant, the scholar will be so too; and thus it is with teachers, and their people under their care; if the leaders are blind and ignorant, those under their instructions will remain so likewise. These words are an illustration of the preceding parable, and are used to another purpose here than in Mat 10:24. See Gill on Mat 10:24. but every one that is perfect shall be as his master. The Vulgate Latin reads it, "every one shall be perfect if he is as his master"; that is, if his master is a man of general learning, and a complete scholar, if he is like him, he will be so too: the Persic version renders it, "every disciple that desires perfection shall be as his master": whoever is ambitious of being a thorough scholar, and is diligent and industrious, by all ways and means, to obtain such a character, shall be even as good an one as his master, under whom he learns, and better he cannot well expect to be; and this is sufficient; and so the Ethiopic version renders it, "is it not enough that every one be as his master?" agreeably to Mat 10:25 Maimonides (i) has an expression much like this: "he that learns, shall not be greater than he of whom he learns, but shall be, "as he".'' Christ, in this last clause, seems to design his own disciples, who, when perfect in knowledge, which is not to be expected in this state, unless in a comparative sense, will be like himself. (i) Misn. Bava Kama, c. 2. sect. 5.”
Source
1832
A.D.
Adam Clarke Methodist
1762–1832
“Can the blind lead the blind? - This appears to have been a general proverb, and to signify that a man cannot teach what he does not understand. This is strictly true in spiritual matters. A man who is not illuminated from above is utterly incapable of judging concerning spiritual things, and wholly unfit to be a guide to others. Is it possible that a person who is enveloped with the thickest darkness should dare either to judge of the state of others, or attempt to lead them in that path of which he is totally ignorant! If he do, must not his judgment be rashness, and his teaching folly? - and does he not endanger his own soul, and run the risk of falling into the ditch of perdition himself, together with the unhappy objects of his religious instruction?”
Source
1871
A.D.
1871
“Can the blind, &c.--not in the Sermon on the Mount, but recorded by Matthew in another and very striking connection (Mat 15:14).”
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.