'Horns of the Altar' in the Bible

And Adonijah feared because of Solomon, and arose and went and caught hold of the horns of the altar.

And it was told Solomon saying, Behold, Adonijah fears king Solomon; for behold, he has caught hold of the horns of the altar, saying, Let king Solomon swear to me this day that he will not put his servant to death with the sword.

And the report came to Joab (for Joab had turned after Adonijah, though he had not turned after Absalom); and Joab fled to the tent of Jehovah, and caught hold of the horns of the altar.