'Thousand' in the Bible

Yahweh, the God of your fathers, make you a thousand times as many as you are, and bless you, as he has promised you!

Know therefore that Yahweh your God, he is God, the faithful God, who keeps covenant and loving kindness with them who love him and keep his commandments to a thousand generations,

How could one chase a thousand, and two put ten thousand to flight, unless their Rock had sold them, and Yahweh had delivered them up?