Proto-MSA

*bir- - son (Kogan 2015: 578)

PS
*bin- - son (Kogan 2014: 89, Kogan 2015: 398)
Akkadian reflexes of *bin- (binu, bintu and bunu, buntu in AHw. 127, 138) are so marginal that make one suspect a WS import (Kogan 2011: 235).

Mehri
bər - son (ML 54)
pl. ḥə-būn
Jibbali
bɛr - son (JL 27–28)
pl. mín