Psalms 115:9

9. O Israel, trust thou in the Lord From the disgusting picture of idols and idol worshippers, the author turns to Jehovah, the object of Israel’s “trust,” “their help and shield.” This change in the strain of the psalm, Perowne thinks, “must unquestionably have been accompanied by a change in the music.” The exhortation to trust, founded on the doctrine of Psalms 33:20, contrasts with the nothingness of idols and the depraving effect of idol worship.

Help Coupled with shield, should be understood in the military sense of succour. A threefold division of Israel is here given Israel, the house of Aaron, and those who fear God; to which the “house of Levi” is added, Psalms 135:20.

Their help That is, that of all those who fear God and trust him.