What was the relationship between Abraham and Isaac?
Isaac was the son of Abraham and Sarah. Abraham was a hundred years old when he was born. Genesis 21:2-5
What the Bible says
Genesis 21:3
And Abraham called the name of his son, whom Sara bore him, Isaac.
Genesis 21:5
When he was a hundred years old: for at this age of his father was Isaac born.
Douay-Rheims Bible (Challoner revision), public domain.
What the Church teaches
Abraham’s hope was fulfilled in Isaac, and it was purified by the test of the sacrifice.
Catechism 1819 · Catechism of the Catholic Church
Did you know?
On the way up the mountain, Isaac asked Abraham where the lamb was. Abraham answered that God himself would provide. Genesis 22:7-8