“... The continuation of the answer uses the third person singular verb, which makes God the subject of the second verb. God gave a commandment, and then God turned to friends. In this part of the response, Ps.-Aristeas comes close to the wording of Deut 13:7 from which he seems to have lifted his phraseology, although the context of Deuteronomy differs completely from Aristeas. There the friend is called “one who is like your own soul” (ὁ φίλος ὁ ἴσος τῆς ψυχῆς σου), and here the phrase is ἴσον τῇ ψυχῇ τὸν φίλον. Ps.-Aristeas has also adapted the meaning, since in Deuteronomy the friend “who is like your own soul” is the perfect friend, one of a number of possible friends, perhaps more colloquially a bosom-buddy. In Aristeas, all friends are like one’s own self. Of course, similar ideas can be found in Greek literature. So, for example, according to Diogenes Laertius (5.1.20), Aristotle expressed a very similar idea in different language when he said that friends are the “same soul dwelling in two bodies” (μία ψυχὴ δύο σώμασιν ἐνοικοῦσα). Even if he knew Greek sentiments like the one attributed to Aristotle, however, the close wording of this passage to the Deuteronomy text, like the commandment to honor parents, convinces me that the pentateuchal text is Ps.-Aristeas’s proximate source here. ...”

“... 228. God has given the greatest commandment concerning honor to parents This evidently cites the fifth commandment. (Exod. 20:12). friend the equal of a man’s soul The phrase derives from the LXX version of Deut. 13:7. See also Sir. 6:11. ...”