Bible Verses About Servants: By birth

And when Abram heard that his brother was taken captive, he led forth his trained men, born in his house, three hundred and eighteen, and pursued as far as Dan.

O Jehovah, truly I am thy servant: I am thy servant, the son of thy handmaid; Thou hast loosed my bonds.

Is Israel a servant? is he a home-born slave? why is he become a prey?