“It is my Father glorifying me: the one whom you state that, ‘He is our God.’ And you do not know him, in fact I myself discern him.”
Ah! This is really different. Jesus’ opponents know deep inside that he is glorious – they see him and all he teaches and does to and for others. The AD 30 Jews need to know that the LORD God whom they say they worship is the one who is making Jesus great. And Jesus “discerns him”, knows him.
“Even if I might say that I do not discern him I will, resembling you, be a liar. But I do discern him and I am keeping his word.”
Strong words from Jesus. When he says “I am keeping his word”, did his opponents ask themselves whether they – the Jerusalem authorities – were also “keeping his word”? God's word?
“Abraham your father was exceedingly joyful in order that he might see my day, and he saw and rejoiced.”
This matter of Abraham needs to be cleared up. Jesus is saying that Abraham, 2000 years earlier, in fact rejoiced greatly in expectation that he would see the provision that the LORD God would make for him. How?
In the Bible’s first book, Genesis, there is reported the command of the LORD God to Abraham to sacrifice his own son Isaac, as an offering on Mount Moriah. Abraham, believing in the LORD God, went ahead to do that despite everything. Asked by Isaac about the offering to be made, Abraham told him, “God will provide for himself the lamb for a burnt offering, my son.” He did.
So, yes, Abraham did look ahead to the day when God would provide his own Son, the Son of God, as the one true offering for sin - on the cross.
So the Jews said to him, “Fifty years you do not yet have and you discerned Abraham?” Jesus said to them, “Amen, amen I state to you, before Abraham ever came to be, I am!”