When it is said
It is sung at the Presanctified Liturgy, the evening service of Lent at which the Church gives Communion from gifts blessed the Sunday before. It is served on the Wednesdays and Fridays of the fast.
It comes after the reading from Proverbs. The first verse is sung and the choir sings it back, and it comes again after each of the three verses that follow.
Everyone in the church kneels while it is sung, and the priest censes the altar. In the translator Isabel Hapgood’s service book of 1906, the Prayer of St Ephraim follows straight after.
Where it comes from
Author by tradition
The Church’s evening psalm
Psalm 141 is the psalm of Vespers, the Church’s evening service. In 1891 the translator G. V. Shann explained the choice by its second verse, which offers prayer to God like incense and raised hands like the evening sacrifice. At the Presanctified Liturgy that one verse is taken out and sung as a refrain.
G. V. Shann, Euchology (1891), notes on Vespers; Azbyka.ru, the Liturgy of the Presanctified Gifts
Kneeling in turn
The Slavonic service book sets out how the people kneel. Everyone kneels for the first verse and stands at “the lifting up of my hands”. Through the other verses the two choirs take turns, each with its side of the church, so one side kneels while the other sings. At the last refrain the priest gives the censer to the deacon and kneels too.
The Scripture in it
I call upon You, O LORD; come quickly to me. Hear my voice when I call to You. May my prayer be set before You like incense; my uplifted hands, like the evening offering. Set a guard, O LORD, over my mouth; keep watch at the door of my lips. Do not let my heart be drawn to any evil thing or take part in works of wickedness with men who do iniquity; let me not feast on their delicacies.
Bible text: Berean Standard Bible, public domain.
In Church Slavonic
Да исправится молитва моя, яко кадило пред Тобою,
воздеяние руку моею, жертва вечерняя.
Господи, воззвах к Тебе, услыши мя, вонми гласу моления моего, внегда воззвати ми к Тебе.
Положи, Господи, хранение устом моим, и дверь ограждения о устнах моих.
Не уклони сердце мое в словеса лукавствия, непщевати вины о гресех.
Да исправится молитва моя, яко кадило пред Тобою.
Воздеяние руку моею, жертва вечерняя.
From the Liturgy of the Presanctified Gifts in Church Slavonic, on Azbyka.ru, a Russian Orthodox website.