Possibly then Terah may have been induced to move northwards by a desire to shake himself free from customs he disapproved. The Hebrews themselves seem always to have considered that his migration had a religious motive. "This people," says one of their old writings, "is descended from the Chaldeans, and they sojourned heretofore in Mesopotamia because they would not follow the gods of their fathers which were in the land of Chaldea. For they left the way of their ancestors and worshipped the God of heaven, the God whom they knew; so they cast them out from the face of their gods, and they fled into Mesopotamia and sojourned there many days. Then their God commanded them to depart from the place where they sojourned and to go into the land of Canaan." But if this is a true account of the origin of the movement northwards, it must have been Abraham rather than his father who was the moving spirit of it; for it is certainly Abraham and not Terah who stands as the significant figure inaugurating the new era. If doubt rests on the moving cause of the migration from Ur, none rests on that which prompted Abraham to leave Charran and journey towards Canaan. He did so in obedience to what he believed to be a Divine command, and in faith on what he understood to be a Divine promise. How he became aware that a Divine command thus lay upon him we do not know. Nothing could persuade him that he was not commanded. Day by day he heard in his soul what he recognised as a Divine voice, saying: "Get thee out of thy country and from thy kindred and from thy father's house, unto a land that I will show thee!" This was God's first revelation of Himself to Abraham. Up to this time Abraham to all appearance had no knowledge of any God but the deities worshipped by his fathers in Chaldea. Now, he finds within himself impulses which he cannot resist and which he is conscious he ought not to resist. He believes it to be his duty to adopt a course which may look foolish and which he can justify only by saying that his conscience bids him. He recognises, apparently for the first time, that through his conscience there speaks to him a God Who is supreme. In dependence on this God he gathered his possessions together and departed.