Charles Ellicott Commentary Psalms 118:26

"Blessed be he that cometh in the name of Jehovah: We have blessed you out of the house of Jehovah." — Psalms 118:26 (ASV)

Blessed ... —These words of welcome are probably spoken by the Levite in charge, to the procession approaching the gates. According to Rabbinical writings, pilgrim caravans were welcomed in this way on their arrival at Jerusalem.