Leslau is likely correct to relate Proto-MSA *ṣḥr ‘to brand’ to Hbr. ṣāḥōr ‘reddish-gray’ (HALOT 1019), Syr. ṣḥar ‘erubuit’ (LSyr. 626), Arb. ṣḥr (XI) ‘to dry up, to become yellow,’ ṣaḥīrat- ‘milk into which heated stones are thrown’ (Lane 1654), implying an original meaning “to burn,” “to be burnt” (cf. especially Ugr. ṣḥrr ‘to be burnt,’ ‘to roast,’ DUL 782). One might be tempted to relate to this root Tgr.
ṣäḥarä ‘to take up and carry away coal and ashes’, Tna.
ṣäḥarä ‘to stir a fire’, but the general meaning of the Tigrinya verb seems rather to be ‘to scoop up, to scrape up with the hands, to shoveľ (Kogan 2015:569-570)