PC

*nabk- - spring, stream (HALOT 663, Kogan 2015: 299)

with word-final devoicing *g > k

PCS
*nbg - to spring up (Kogan 2015: 299)

Ugaritic
nbk - fountain, spring (DUL 609)
Ugaritic
nbk, npk - fountain, spring (DUL 617)
Hebrew
mibbəkī nəhārōt - source of the rivers (Job 28:11)
comp. Ugaritic mbk nhrm ‘source of the rivers’ (KTU 14.4.21)
Hebrew
nēbäk - source (HALOT 663)
Hebrew
nibkē yām - sources of the sea (Job 38:16)