Tantum Ergo

Tantum Ergo is the incipit of the last two verses of Pange Lingua, a Medieval Latin hymn written by St Thomas Aquinas c. 1264. The Genitori Genitoque and Procedenti ab Utroque portions are adapted from Adam of Saint Victor's sequence for Pentecost. The hymn's Latin incipit literally translates to “Therefore so great.”

The singing of Tantum Ergo occurs during veneration and benediction of the Blessed Sacrament in the Roman Catholic Church and other denominations that have this devotion. It is usually sung, though solemn recitation is sometimes done, and permitted.

A century-old translation and still used in Catholic churches liturgically renders the hymn thus, in a form which can be sung to the same music as the Latin:

Other, more modern English translations exist and are also used in Catholic churches liturgically.

The words "procedenti ab utroque / compar sit laudatio"—literally, "May equal praise be to the One proceeding from both"—refer to the Holy Spirit, who according to the later version of the Nicene Creed used in Western Christianity proceeds from both the Father and the Son. The view that the Spirit proceeds from the Son as well is disputed by many Eastern Christians.

A partial indulgence is granted to the faithful, who devoutly recite the Tantum Ergo. But a plenary indulgence is granted on Holy Thursday and on the feast of Corpus Christi, if it is recited in a solemn manner.

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