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Kitto's Popular Cyclopedia of Biblial Literature
Hosan´na a form of acclamatory blessing or wishing well, which signifies, Save now! Succor now! Be now propitious! It occurs in (also; )—'Hosanna to the Son of David; Blessed is he that cometh in the name of the Lord; Hosanna in the highest!' This was on the occasion of our Savior's public entry into Jerusalem, and, fairly construed, would mean, 'Lord, preserve this Son of David; heap favors and blessings on Him!' It is further to be observed that Hosanna was a customary form of acclamation at the Feast of Tabernacles. This feast was celebrated in September, just before the commencement of the civil year; on which occasion the people carried in their hands bundles of boughs of palms, myrtles, etc. They then repeated , which commence with the word Hosanna; and from this circumstance they gave the boughs, and the prayers, and the feast itself, the name of Hosanna. They observed the same forms also at the Encaenia (;; ) and the Passover. And as they celebrated the Feast of Tabernacles with great joy and gladness, in like manner, on this occasion, did they hail the coming of the Messiah, whose advent they believed to be represented in all the feasts.
Kitto, John, ed. Entry for 'Hosanna'. "Kitto's Popular Cyclopedia of Biblial Literature". https://www.studylight.org/encyclopedias/eng/kbe/h/hosanna.html.