Kitto's Popular Cyclopedia of Biblial Literature
There was no name which conveyed to the Jews the same associations as that of Abraham. As undoubtedly he was in the highest state of felicity of which departed spirits are capable, 'to be with Abraham' implied the enjoyment of the same felicity; and 'to be in Abraham's bosom' meant to be in repose and happiness with him. The latter phrase is obviously derived from the custom of sitting or reclining at table which prevailed among the Jews in and before the time of Christ [ACCUBATION]. It was quite usual to describe a just person as being with Abraham, or as lying on Abraham's bosom; and as such images were unobjectionable, Jesus accommodated his speech to them, to render himself the more intelligible by familiar notions, when, in the beautiful parable of the rich man and Lazarus, he describes the state of the latter after death under these conditions (Luke 16:22-23).
Kitto, John, ed. Entry for 'Abraham's Bosom'. "Kitto's Popular Cyclopedia of Biblial Literature". https://www.studylight.org/encyclopedias/eng/kbe/a/abrahams-bosom.html.