'Thousand' in the Bible

Yahweh, the God of your ancestors, may he add to you as you are [now] a thousand times, and may he bless you just as he {promised you}.

[So] know that Yahweh your God, he [is] God, the trustworthy God, maintaining his covenant and his loyal love with those who love him and with those who keep his commandments to a thousand generations,

How could one chase a thousand and two could cause a myriad to flee, if their Rock had not sold them, and Yahweh had [not] given them up?