Arabic

ṣwb - to appear in a place where he/it should remain, (II) to declare to be right, to approve, (IV) to go right, to reach its goal’, (X) to consider to be right (Lane 1739)

PWS

*ṣwb - to be fitting (SEDonline)

One wonders whether PWS *wṣb/*nṣb ‘to stand, to be erect; to be firm, stable’ may be further related as variant roots.