Albert Barnes Commentary Psalms 115:14

"Jehovah increase you more and more, You and your children." — Psalms 115:14 (ASV)

The Lord shall increase you more and more — He will increase your numbers and your power. We may suppose that the people were greatly diminished by the captivity, and that on their return to their country their number was comparatively small. This promise of a great increase was in accordance with the cherished wishes of the Hebrew people, and with the repeated promises which God had made to their fathers. Compare Genesis 15:5; Genesis 22:17; Genesis 32:12.

You and your children — The blessing shall be not only on you, but it shall go down to future generations.