Armed, and carrying bows. — Following Jeremiah 4:29, and from analogy with Jeremiah 44:9 (“handle and bend the bow”) we get as literal rendering of the Hebrew here, drawing and shooting with the bow. LXX. and Vulgate, “bending and shooting with the bow.” But a close comparison of this verse with Psalms 78:57 of this psalm, and with Hosea 7:16, has suggested to a recent commentator a much more satisfactory explanation, The sons of Ephraim (are like men) drawing slack bowstrings which turn back in the day of battle. “Both the disappointment on the day of battle and the cause of the disappointment, which are mentioned in the text, will be appreciated by the English reader who remembers that the result of the battle of Creçy was determined at the outset by a shower of rain which relaxed the strings of our enemy’s bows” (Burgess, Notes on the Hebrew Psalms.)[15]
[15] This translation assumes that the primitive meaning of the verb râmah is was slack. Certainly the root idea of the word (comp. the cognate râphah and the meaning of the derivation in Proverbs 10:4; Proverbs 12:24) seems to have been relaxation. That turned back, both here and in Psalms 78:57, refers to the recoil of a bow, seems indubitable.
By taking this sense of a comparison of the general character of Ephraim to a bow with a relaxed string that fails at the moment it is wanted (a figure made more expressive by the fact that archery was a practice in which Ephraim excelled), we are freed from the necessity of conjecturing a particular incident to account for this verse, which seems to break the sequence of thought. The whole historical retrospect is intended to lead up to the rejection of the northern kingdom (represented by Ephraim), but the poet is unable to keep back his climax, and thrusts it in here almost parenthetically.