In what day soever I shall call upon thee, hear me: thou shall multiply strength in my soul.

“"In what day soever I call upon Thee, do Thou quickly hear me" (ver. 3). Wherefore, "quickly"? Because Thou hast said, "While yet thou art speaking I will say, Lo, here I am." Wherefore, "quickly"? Because now I seek not earthly happiness, I have learnt holy longings from the New Testament. I seek not earth, nor earthly abundance, nor temporal health, nor the overthrow of my enemies, nor riches, nor rank: nought of these do I seek: therefore "quickly hear me." Since Thou hast taught me what to seek, grant what I seek. ...Let us see then what he seeketh, with what right he hath said, "quickly hear me." For what seekest thou, that thou shouldest quickly be heard? "Thou shalt multiply me." In many ways may multiplication be understood. ...For men are multiplied in their soul with cares: a man seemeth to be multiplied in soul, in whom vices even are multiplied. That is the multiplication of want, not of fulness. What then dost thou desire, thou who hast said, "quickly hear me," and hast withdrawn thyself entirely from the body, from every earthly thing, from every earthly desire, so as to say to God, "Thou shalt multiply me in my soul"? Explain yet further what thou desirest. Thou shalt multiply me, saith he, in my soul "with virtue." ...”

“In the day when I cried thou answeredst me,.... When in distress through Saul's persecution, he cried to the Lord, and he immediately answered him, and delivered him out of his troubles; and such immediate answers of prayer are to be remembered with thankfulness: see Psa 18:6; and strengthenedst me with strength in my soul; put him good heart and spirit, when before ready to faint; strengthened his heart and grace in it, particularly faith, and drew it forth into lively act and exercise so that he sunk not under the weight of affliction and trouble, but was filled with courage to withstand his enemies, and with strength to do the will and work of God; this is to be understood of inward spiritual strength; see Eph 3:16.”

“There are two things for which the poet gives thanks to God: He has answered him in the days of trouble connected with his persecution by Saul and in all distresses; and by raising him to the throne, and granting him victory upon victory, and promising him the everlasting possession of the throne, He has filled him with a proud courage, so that lofty feeling has taken up its abode in his soul, which was formerly fearful about help. Just as רהב signifies impetuosity, vehemence, and then also a monster, so הרהיב signifies both to break in upon one violently and overpowerlingly (Sol 6:5; cf. Syriac arheb, Arabic arhaba, to terrify), and to make any one courageous, bold, and confident of victory. בּנפשׁי עז forms a corollary to the verb that is marked by Mugrash or Dech: so that in my soul there was עז, i.e., power, viz., a consciousness of power (cf. Jdg 5:21). The thanksgiving, which he, the king of the promise, offers to God on account of this, will be transmitted to all the kings of the earth when they shall hear (שׁמעוּ in the sense of a fut. exactum) the words of His mouth, i.e., the divine אמרה, and they shall sing of (שׁיר with בּ, like דּבּר בּ in Psa 87:3, שׂיח בּ in Psa 105:2 and frequently, הלּל בּ in Psa 44:9, הזכּיר בּ in Psa 20:8, and the like) the ways of the God of the history of salvation, they shall sing that great is the glory of Jahve. Psa 138:6 tells us by what means He has so super-gloriously manifested Himself in His leadings of David. He has shown Himself to be the Exalted One who is His all-embracing rule does not leave the lowly (cf. David's confessions in Psa 131:1; Sa2 6:22) unnoticed (Psa 113:6), but on the contrary makes him the especial object of His regard; and on the other hand even from afar (cf. Psa 139:2) He sees through (ידע as in Psa 94:11; Jer 29:23) the lofty one who thinks himself unobserved and conducts himself as if he were answerable to no higher being (Psa 10:4). In correct texts וגבה has Mugrash, and ממרחק Mercha. The form of the fut. Kal יידע is formed after the analogy of the Hiphil forms ייליל in Isa 16:7, and frequently, and ייטיב in Job 24:21; probably the word is intended to be all the more emphatic, inasmuch as the first radical, which disappears in ידע, is thus in a certain measure restored. (Note: The Greek imperfects with the double (syllabic and temporal) augment, as ἑώρων, ἀνέῳγον, are similar. Chajuǵ also regards the first Jod in these forms as the preformative and the second as the radical, whereas Abulwald, Gramm. ch. xxvi. p. 170, explains the first as a prosthesis and the second as the preformative. According to the view of others, e.g., of Kimchi, יידע might be fut. Hiph. weakened from יהדע (יהידיע), which, apart from the unsuitable meaning, assumes a change of consonants that is all the more inadmissible as ידע itself springs from ודע. Nor is it to be supposed that יידע is modified from יידע (Luzzatto, 197), because it is nowhere written יידע.)”