Biblical Commentary on the Old Testament
Psalms 69
We see at once at the very beginning, in the omission of the רצה (Psa 40:14), that what we have here before us is a fragment of Ps 40, and perhaps a fragment that only accidentally came to have an independent existence. The להצּילני, which was under the government of רצה, now belongs to הוּשׁה, and the construction is without example elsewhere. In Psa 70:3 (= Psa 40:15) יחד and לספּותהּ are given up entirely; the original is more full-toned and soaring. Instead of ישׁמּוּ, torpescant, Psa 70:4 has ישׁוּבוּ, recedant (as in Ps 6:11, cf. Psa 9:18), which is all the more flat for coming after יסגו אחור. In Psa 70:4, after ויאמרים the לי, which cannot here (cf. on the contrary, Psa 35:21) be dispensed with, is wanting.
ויאמרו instead of יאמרו is unimportant. But since the divine name Jahve is now for once chosen side by side with Elohim, it certainly had a strong claim to be retained in Psa 70:5. Instead of תּשׁועתך we have ישׁועתך here; instead of עזרתי, here עזרי. And instead of אדני יחשׁב לי we have here אלהים חוּשׁה־לּי - the hope is turned into petition: make haste unto me, is an innovation in expression that is caused by the taking over of the לי.
You arrive at the cited line; the whole work is yours to read around it. The text is set from the cited public-domain edition.