Judges 11:31

The words of this verse prove conclusively that Jephthah intended his vow to apply to human beings, not animals: for only one of his household could be expected to come forth from the door of his house to meet him. They also preclude any other meaning than that Jephthah contemplated a human sacrifice. This need not, however, surprise us, when we recollect his Syrian birth and long residence in a Syrian city, where such fierce rites were probably common. The Syrians and Phoenicians were conspicuous among the ancient pagan nations for human sacrifices, and the transfer, under such circumstances, to Yahweh of the rites with which the false gods were honored, is just what one might expect.