First introduced in chapter twelve of Genesis, in which he is called by God to leave his home for another land. Originally from Ur, Abraham migrates via Haran to the land of Canaan. This is significant to Judaism because it is seen as establishing a claim to the region now called Israel. Abraham's migration becomes a pilgrimage of great importance, making him, his son Isaac, and his grandson Jacob the patriarchs of Judaism.
In return for God's promise to provide land, protection, and descendants, Abraham and his male descendants must be circumcised as a sign of their executive relationship with God.
Abraham has long been unable to have a son by his wife, Sarah, and a Sarah's urging, he fathers her by her maid, Hagar, a son named Ishmael. Soon after, Sarah herself has a son and demands Ishmael and Hagar be sent away.
God asks Abraham to offer Isaac as a sacrifice, in which Abraham agrees and sets out to Mount Moriah. Just before the boy is to die, God stops Abraham, and a ram is used as the sacrifice instead. God had tested Abraham's devotion, and is so providing his absolute loyalty to God, Abraham has shown himself worthy of land, wealth, fame, and the joy of knowing he will have innumerable descendants.