Jamieson, Fausset and Brown on 1 Kings 17:6

6. the ravens brought him bread--The idea of such unclean and voracious birds being employed to feed the prophet has appeared to many so strange that they have labored to make out the Orebim, which in our version has been rendered "ravens," to be as the word is used (in Eze 27:27) "merchants"; or Arabians (2Ch 21:16; Ne 4:7); or, the citizens of Arabah, near Beth-shan (Jos 15:6; 18:18). But the common rendering is, in our opinion, preferable to these conjectures. And, if Elijah was miraculously fed by ravens, it is idle to inquire where they found the bread and the flesh, for God would direct them. After the lapse of a year, the brook dried up, and this was a new trial to Elijah's faith.

1Ki 17:8-16. He Is Sent to a Widow of Zarephath.