A.T. Robertson Commentary Matthew 2:12

"And being warned [of God] in a dream that they should not return to Herod, they departed into their own country another way." — Matthew 2:12 (ASV)

Warned in a dream (χρηματισθεντες κατ' οναρ). The verb means to transact business (χρηματιζω from χρημα, and that from χραομα, to use. Then to consult, to deliberate, to make answer as of magistrates or an oracle, to instruct, to admonish. In the Septuagint and the New Testament it occurs with the idea of being warned by God and also in the papyri (Deissmann, Bible Studies, p. 122). Wycliff puts it here: "An answer taken in sleep."