Albert Barnes Commentary Psalms 115:9

"O Israel, trust thou in Jehovah: He is their help and their shield." — Psalms 115:9 (ASV)

O Israel, trust thou in the Lord - This exhortation is largely founded on what had just been said regarding idols. They had no power. There was no reason why they should be trusted. They could not help in the day of trouble; and as people need a god, and as the idols cannot be to them as gods, the exhortation is addressed to His people to trust Him. He would be to them all that was implied in the name God; all that was wanted in a God.

He is their help - The help of those who trust in Him. He is able to help them in the time of trouble; He is willing to help them; He will help them. Those who put their trust in Him will find Him a sure and certain help. This is the experience of all who trust in Him.

And their shield - Their protector. See Psalm 5:12, note; Psalms 18:2, note; Psalms 33:20, note. Compare Genesis 15:1; Deuteronomy 33:29; Proverbs 30:5.