A raven was sent out of the ark by Noah (Gen. 8: 6), but it was regarded as ceremonially unclean in the Law (Lev. 11: 15, in the Priestly source). The prophet Elijah was brought bread by ravens when he lived east of the Jordan (1 Kgs. 17: 6).
Citation for raven
Citation styles are based on the Chicago Manual of Style, 15th Ed., and the MLA Style Manual, 2nd Ed..
MLA
"raven." In A Dictionary of the Bible. Ed. W. R. F. Browning. Oxford Biblical Studies Online. May 18, 2013. <http://www.oxfordbiblicalcstudies.com/article/opr/t94/e1589>.
Chicago
"raven." In A Dictionary of the Bible. , edited by W. R. F. Browning. Oxford Biblical Studies Online, http://www.oxfordbiblicalcstudies.com/article/opr/t94/e1589 (accessed May 18, 2013).