Tna. -ˁ- shows that the «correct» laryngeal in Gez. is not -ˀ- but -ˁ-.
Tigrinya
ˀəngera - bread (actually a large, flat, pankcake-like comestible made of batter)
(TED 1495)
Tigrinya
ˀənkab - from, starting from, from... on; with regard to, with respect to, in relation to
(TED 1489)
Likely a combination of ˀən- (probably, the same element as in Geez ˀənbala, which may ultimately be identical to Akk. ina) *kV, not preserved in Tigrinya as an independent preposition, and ab ‘in’ (Arakelova 2001:18).