Deus in adjutorium

Deus, in adjutorium meum intende, with the response Domine, ad adjuvandum me festina (respectively, "O God, come to my assistance" and "O LORD, make haste to help me") are the first verse of Psalm 69 (Psalm 70 in the KJV: "Make haste, O God, to deliver me; Make haste to help me, O LORD."; Hebrew: לַ֝מְנַצֵּ֗חַ לְדָוִ֥ד לְהַזְכִּֽיר׃ אֱלֹהִ֥ים לְהַצִּילֵ֑נִי יְ֝הוָ֗ה לְעֶזְרָ֥תִי חֽוּשָֽׁה׃‎‎ ’Ĕlōhîm lə-haṣṣîlênî Yahweh lə-‘ezrāṯî ḥūšāh). In this form they are a traditional Latin Christian prayer.

These words form the introductory prayer to every Hour of the Roman, Ambrosian, and monastic Breviaries, except during the last three days of Holy Week, and in the Office of the Dead. While these are recited or sung, all present bless themselves with the sign of the cross.

Tradition says that Benedict of Nursia introduced this custom into the monastic Office and that Gregory the Great extended it to all the Roman churches; Cassian (Coll., X, 10), however, says that from the earliest Christian times the monks used this introduction very often, probably outside of the liturgical prayers.

In placing this supplication at the beginning of every Hour, the Catholic Church implores the assistance of God against distractions in prayer. In the Roman Rite, the "Deus in adjutorium" is preceded in Matins by the "Domine, labia mea aperies" ("Open Thou, o LORD my lips), whilst in the monastic Breviary, the order is reversed. In Compline, it is always preceded by the "Converte nos, Deus".

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