John Gill's Exposition of the Whole Bible
Psalms 141:2
Let my prayer be set forth before thee [as] incense,.... Which was offered every morning on the altar of incense, at which time the people were praying, Exodus 30:1; and was an emblem of it, even of pure, holy, and fervent prayer; which being offered on the altar Christ, which sanctifies every gift, and by him the High Priest; through whom every sacrifice is acceptable unto God; and through whose blood and righteousness, and the sweet incense of his mediation and intercession, it becomes fragrant and a sweet odour to the Lord; and being directed to him, it goes upwards, is regarded by him, and continues before him as sweet incense; which is what the psalmist prays for; see Malachi 1:11;
[and] the lifting up of my hands as the evening sacrifice; the burnt sacrifice of the evening, according to Ben Melech, the lamb slain every evening; or else the minchah, as the word is; the meat, or rather the bread offering made of fine flour, with oil and frankincense on it, which went along with the former, Exodus 29:38; and so the Targum,
"as the sweet gift offered in the evening.''
This only is mentioned, as being put for both the morning and the evening sacrifice; or because the incense was offered in the morning, from which it is distinguished: or it may be, as Kimchi thinks, this psalm was composed in the evening; and so the inscription in the Syriac version is,
"a psalm of David, when he meditated the evening service.''
Or because this was the last sacrifice of the day; there was no other after it, as Aben Ezra observes; and the most acceptable; to which may be added, that this was the hour for prayer, Acts 3:1. Wherefore "lifting up of [the] hands" was a prayer gesture, and a very ancient one both among Jews and Gentiles x; Aristotle y says, all men, when we pray, lift up our hands to heaven; and it is put for that itself, 1 Timothy 2:8; and is desired to be, like that, acceptable unto God; as it is when the heart is lifted up with the hands, and prayer is made in the name and faith of Christ.
x Vid. Barthii Animadv. in Claudian. ad Rufin. l. 2. v. 205. y De Mundo, c. 6. Vid. Plutarch. in Vita Camilli. "Sustulit ad sidera palmas", Virgil. Aeneid. 2. so Ovid. Fasti, l. 3.