Deuteronomy 18:21-22 -

The test by which it was to be discovered which was the true prophet and which the false, was the fulfillment or non-fulfillment of his prediction. The reference here is to the prediction of proximate events—events that were to happen within a limited period, but which were not such as one not divinely instructed could foresee. When such came to pass, the pretensions of the prophet were thereby substantiated, and his authority established (cf. 1 Samuel 3:19 ; John 2:18 , etc.). This was a more certain test than such as was offered by signs and wonders ( Deuteronomy 13:2 , etc.).

HOMILETICS