Exegesis:

en biblō psalmōn ‘in the book of psalms.’ For biblos cf. on 3.4.

psalmos (also 24.44) ‘song of praise,’ ‘psalm,’ in Luke in the plural and referring to the Old Testament book of Psalms.

For a detailed treatment of the rest of vv. 42f, containing the quotation from Psalm 110.1. The text of Mark and Luke is identical with the one exception that Luke following the Septuagint reads hupopodion tōn podōn sou instead of hupokatō. For kurios and tō kuriō mou cf. on 1.6, sub (4) and (3) respectively.

hupopodion ‘footstool.’

Translation:

In the Book of Psalms, or, ‘in the part of the Scripture called the Psalms,’ or simply, ‘in the Psalms.’ For book see on 4.17. Psalms, often transliterated, may be translated as ‘chanting’ (Ekari), ‘songs’ (Shona 1966, Tae’), ‘Holy Songs’ (Trukese), ‘holy songs of old’ (Uab Meto), ‘songs of worship/praise.’ In some predominantly Muslim countries one of the Arabic terms for the Psalms, i.e. zabur, or mazmur (etymologically related to Hebr. mizmor), has been transliterated.

For the Lord and my Lord see on 1.6, sub (c) and (b). If the term for “Lord” is obligatorily possessed, the first phrase may have to become ‘our Lord’ (Dan).

Sit, the aspect is ingressive and continuative: sit down (or, take a seat) and remain seated.

My right hand, cf. also on 1.11, ad (1) and references.

(V. 43) Till here has the meaning of ‘during the time that,’ ‘and in the meanwhile.’

Enemies, see on 1.71.

A stool for thy feet. In this metaphor, which sometimes is better rendered as a simile, any term will do that refers to something that is put under the feet of a person sitting in state, such as, ‘cushion,’ ‘carpet,’ ‘small-bank’ (Sranan Tongo), ‘footstick’ (Highland Totonac). It may be preferable, however, to use a culturally equivalent figure of speech for subjection of enemies; or to shift to a non-figurative rendering, e.g. ‘I subject your enemies to you,’ ‘I defeat your enemies for you’; or to combine a figurative and a non-figurative rendering, e.g. ‘I beat down to the ground your enemies and put them underneath your feet like grass’ (Enxet).

Quoted with permission from Reiling, J. and Swellengrebel, J.L. A Handbook on the Gospel of Luke. (UBS Handbook Series). New York: UBS, 1971. For this and other handbooks for translators see here . Make sure to also consult the Handbook on the Gospel of Mark for parallel or similar verses.