Jesus said to them, “Most assuredly, I say to you, before Abraham was, I AM.” John 8:58

“Then they took up stones to throw at Him; but Jesus hid Himself and went out of the temple, going through the midst of them, and so passed by.” John‬ ‭8‬:‭59‬

[ Moses asked God about His name…

And God said to Moses, “I AM WHO I AM.” And He said, “Thus you shall say.. ‘I AM has sent me to you.’ ” Exodus‬ ‭3‬:‭13-14‬ ]

The Jews understood Jesus claimed to be God when Jesus said before Abraham was, “I AM” – Jesus used the very name of God! This provoked the Jews to want to kill him.
Since God is eternal there is to Him no ‘was’ or ‘will be’. He always ‘is’. What Jesus really says here is: ‘Before Abraham was, I am eternally alive!’