C. F. Keil and Franz Delitzsch on Psalms 115:1

Call to the God of Israel, the Living God, to Rescue the Honour of His Name

This Psalm, which has scarcely anything in common with the preceding Psalm except that the expression “house of Jacob,” Psa 114:1, is here broken up into its several members in Psa 115:12., is found joined with it, making one Psalm, in the lxx, Syriac, Arabic and Aethiopic versions, just as on the other hand Ps 116 is split up into two. This arbitrary arrangement condemns itself. Nevertheless Kimchi favours it, and it has found admission into not a few Hebrew manuscripts.

It is a prayer of Israel for God’s aid, probably in the presence of an expedition against heathen enemies. The two middle strophes of the four are of the same compass. Ewald’s conjecture, that whilst the Psalm was being sung the sacrifice was proceeded with, and that in Psa 115:12 the voice of a priest proclaims the gracious acceptance of the sacrifice, is pleasing. But the change of voices begins even with Psa 115:9, as Olshausen also supposes.