Akkadian

ṣētu - light, shining appearance of the sun, moon and stars, sultry weather, open air, open sun (CAD Ṣ 150, AHw. 1095)

AHw: ‘Glut, heller Schein, Hitze’.

*ṣḥw/*ṣ̂ḥw - to shine, to be bright (CDG 149, Appleyard 1977:39, Kogan 2015: 446)

Gez. ṣ̂aḥāy, Tna. ṣäḥay, Amh. ṭay, Eža č̣et (CDG 149) derive from this root