Jesus simply confirming he was - Jesus of Nazareth, no more and no less.
---------------
"Before Abraham I am" = In the mind and plans of God (Eph 3:9 etc), the Jesus to be was first cap off the ranks, hence before a plan for an Abraham, there was a plan for a Jesus to be.
John 18:6
Therefore when He said to them, “I am He,” they drew toward the back and fell to the ground.
Wotsup,
The above verse is spoken on the night Jesus was betrayed.
These are about the last words Thomas heard before the arrest of Jesus.
When Jesus spoke these words "I am" the mob that was there to arrest him drew to the back and fell over.
After the resurrection, Thomas would also have recalled this event when he called Jesus "my Lord and my God" .
Jesus is the "I am " from before Abraham
