OSANNA. - A Hebrew acclamation that entered the liturgy following its use in the New Testament (Mt. 21, 9. 15; Mc. 11, 9; Io. 12, 13).
In Latin one finds hosanna or osanna (Greek ὕσπνά), a rendering of the Hebrew hḗfāh-ndā' “save, graciously” (cf. Ps. 118, 25). In practice, as appears from both Christian and Hebrew liturgical usage, the original meaning had been weakened into a simple exclamation of joy and good wishes, similar to our “long live!”, as s. Agostino had already observed (In Ioannem tract., 51, 2: PL 35, 1764). At the request of pope Damaso, S. Girolamo composed a short treatise on the word o. Having reviewed certain impossible meanings devised by persons ignorant of Hebrew, and having examined the various Greek versions and discussed Hebrew philology, he gave the correct explanation (Ep. 20, 1-6: CSEL, LIV, pp. 104-10).
In the Hebrew liturgy o. was repeated especially during the feast of Tabernacles, whose seventh day was also called “the great o.”; in the Christian liturgy, besides occurring in the “Trisagion” of the Mass, the term recurs particularly on Palm Sunday. The Didaché (10, 6) already attests the liturgical use of this word. The ancient custom of greeting bishops with this acclamation has, on the other hand, been lost (cf. s. Girolamo, In Matthaeum, 21, 15: PL 26, 158).