Kumbukumbu la Torati 18 : 22 Deuteronomy chapter 18 verse 22

Atakaponena nabii kwa jina la Bwana, lisifuate jambo lile wala kutimia, hilo ndilo neno asilolinena Bwana; kwa kujikinai amelinena huyo nabii, usimwogope
soma Mlango wa 18

when a prophet speaks in the name of Yahweh, if the thing doesn't follow, nor happen, that is the thing which Yahweh has not spoken: the prophet has spoken it presumptuously, you shall not be afraid of him.