rašû - to obtain, to come into the possession of goods; to have descendants, family (CAD R 193, AHw. 961)

As plausibly suggested in HALOT, DUL and elsewhere, this root has a good chance of being related to PWS *wrṯ (*ṯ is confirmed by Sargonic). Cf. Kogan 2015: 100, 353, 413-414.