Matthew 21:16
και ειπον αυτω ακουεις τι ουτοι λεγουσιν ο δε ιησους λεγει αυτοις ναι ουδεποτε ανεγνωτε οτι εκ στοματος νηπιων και θηλαζοντων κατηρτισω αινον
KJV
And said unto him, Hearest thou what these say? And Jesus saith unto them, Yea; have ye never read, Out of the mouth of babes and sucklings thou hast perfected praise?
Psalm 8:3 (8:2) (Septuagint)
ἐκ στόματος νηπίων καὶ θηλαζόντων κατηρτίσω αἶνον ἕνεκα τῶν ἐχθρῶν σου τοῦ καταλῦσαι ἐχθρὸν καὶ ἐκδικητήν .
Brenton
Out of the mouth of babes and sucklings hast thou perfected praise, because of thine enemies; that thou mightest put down the enemy and avenger.
Psalm 8:3 (Masoretic)
מִפִּי עֹֽולְלִים ׀ וְֽיֹנְקִים יִסַּדְתָּ עֹז לְמַעַן צֹורְרֶיךָ לְהַשְׁבִּית אֹויֵב וּמִתְנַקֵּֽם׃
KJV (Psalm 8:2)
Out of the mouth of babes and sucklings hast thou ordained strength because of thine enemies, that thou mightest still the enemy and the avenger.
Matthew appears at first sight to give a different meaning from that conveyed by the Hebrew יִסַּדְתָּ עֹז in his κατηρτισω αινον. Yet let us examine. The Hebrew verb signifies primarily to set, place, lay, the foundation of anything (see Isaiah 28:16, Ezra 3:10, Ezra 3:12, Isaiah 14:32). And, as laying the foundation is preparatory to raising the building, it is generalized into, to prepare, which is the meaning of the Greek verb. Again, the noun in Hebrew means properly might, power, as inherent in its possessor (see Job 12:16; Psalm 29:11; Judges 9:51); then, splendour, majesty as the concomitants of power (see Habakkuk 3:4; Psalm 96:7). And, as these excite in the mind admiration, which finds utterance in praise, it may appropriately be so rendered here (see Psalm 29:1). And the corresponding word in the Greek expresses the same idea.
Hengstenberg, however, says: “it always signifies might, strength. By taking it in the sense of praise here, the meaning is disfigured.” And yet it has been so rendered by those whom he believes to have been inspired! Besides, in his setting aside the expositions of others, he always uses it as if it meant praise. Thus, he says: “De Wette, without cause, stumbles at the circumstance that praise to God is here ascribed to sucklings. Even a little child is conscious of pleasure in looking upon the lovely scenes of nature, in particular, upon the starry heavens, which are here specifically mentioned; and this admiration of the works of God is a silent praising of Him.” The sense appears to be this: that God has, out of the mouth of children, prepared for Himself a power, to be used against His enemies, which is nothing else than the conscious or unconscious praise they give utterance to, in their admiration of His works, which manifesting His glory, proclaim His existence and perfections.