Luke 16:23
Abraham ... Abraham’s bosom , called such also by Josephus in his Discourse to the Greeks about Hades.
Abraham’s bosom. This same expression (found only here in Scripture) was used in the Talmud as a figure for heaven.
Abraham’s bosom was an idiom for eating next to Abraham at a feast. This would be a reference to a welcoming meal for Jews into the righteous side of hades (paradise, cf. 23:43). - Utley.
It is not a synonym for paradise; but to repose on Abraham’s bosom is to be in paradise, for Abraham is there John 8:56; - Plummer, A.
Abraham’s side (lit., “bosom”), which means he was welcomed into the fellowship of other believers already in heaven, particularly Abraham, the father of the Jewish people. - The ESV Study Bible (p. 1991)