Your father Abraham rejoiced that he would see My day. He saw it and was glad.” Then the Jews said to Him, “You are not yet fifty years old, and You have seen Abraham?” “Truly, truly, I tell you,” Jesus declared, “before Abraham was born, I am!” At this, they picked up stones to throw at Him. But Jesus was hidden and went out of the temple area.
John 8:56-59 (BSB)
Jesus is arguing with a crowd in the temple. Their reply to his last sentence tells us how they heard it.

