Bastard: Ishmael
Source: Nav
Genesis 16:3, 15
So after he had lived in Canaan for ten years, his wife Sarai took her Egyptian maidservant Hagar and gave her to Abram to be his wife. / And Hagar bore Abram a son, and Abram gave the name Ishmael to the son she had borne.
Galatians 4:22
For it is written that Abraham had two sons, one by the slave woman and the other by the free woman.