The LORD hath been mindful of us: he will bless us; he will bless the house of Israel; he will bless the house of Aaron.
The Lord hath been mindful of us - by releasing us from the Babylonian captivity. This group of psalms evidently alludes to some recent deliverance (Psalms 116:17-18: cf. Psalms 107:1-43, introductory notes).
He will bless the house of Israel; he will bless the house of Aaron. This and Psalms 115:13 is the three-fold response and acknowledgment of blessing, answering to the three-fold call to Israel collectively, the house of Aaron, and them that fear the Lord, to trust in Him, and so obtain the blessing (Psalms 115:9-11).