'Freewoman' in the Bible

For it is written that Abraham had two sons, one by the female slave and one by the free woman.

But the one by the female slave was born according to human descent, and the one by the free woman through the promise,

But what does the scripture say? "Drive out the female slave and her son, for the son of the female slave will never inherit with the son" of the free woman.

Therefore, brothers, we are not children of the female slave but of the free woman.