Gospel commented, "Abraham rejoiced to see my day", Saint John 8:51-59.

Jesus said to the Jews: "Amen, amen, I say to you, whoever keeps my word will never see death." 
(So) the Jews said to him, "Now we are sure that you are possessed. Abraham died, as did the prophets, yet you say, 'Whoever keeps my word will never taste death.' 
Are you greater than our father Abraham, who died? Or the prophets, who died? Who do you make yourself out to be?"
Jesus answered, "If I glorify myself, my glory is worth nothing; but it is my Father who glorifies me, of whom you say, 'He is our God.' 
You do not know him, but I know him. And if I should say that I do not know him, I would be like you a liar. But I do know him and I keep his word. 
Abraham your father rejoiced to see my day; he saw it and was glad.
So the Jews said to him, "You are not yet fifty years old and you have seen Abraham?" 
Jesus said to them, "Amen, amen, I say to you, before Abraham came to be, I AM."
So they picked up stones to throw at him; but Jesus hid and went out of the temple area.

Gospel commented, 

"Abraham rejoiced to see my day"

"Your father Abraham rejoiced that he should see my day; and he saw it, and was glad." What is intended? "Abraham believed God, and it was imputed unto him for righteousness." (Gn 15,6; Rm 4,3). In the first place, he believed him to be the maker of heaven and earth, the only God; and secondly, that he would make his posterity to be as the stars of heaven in number. This is what Paul also meant when he said "as lights in the world" (Phil 2,15). Rightly, therefore, having left his earthly kindred, he followed the Word of God, walking as a stranger with the Word that he might later become a citizen with the Word, the Son of God (cf. Eph 2,19). Rightly, too, the apostles, being of the race of Abraham, left their boat and their father, and followed the Word (Mt 4,22). And rightly do we also, having the same faith as Abraham and taking up the cross just as Isaac took up the wood, follow the same Word (Gn 22,6; Mt 16,24). 

For in Abraham people had learned beforehand and become accustomed to follow the Word of God. For Abraham, by his faith, followed the commandment of God’s Word and did not falter in delivering up his only-begotten and beloved son as a sacrifice to God (Gn 22,2) so that God also might be pleased to offer up for all Abraham's descendants his own beloved and only-begotten Son as a sacrifice for our redemption (Rm 8,32).

Since, therefore, Abraham was a prophet and saw in the Spirit the day of the Lord's coming and the dispensation of his suffering, namely salvation for himself and for all those who, like him, would believe in God, he rejoiced exceedingly. The Lord Christ, therefore, was not unknown to Abraham, whose day he desired to see. And it was as one who had been taught by the Word that Abraham also knew the Father of the Lord and believed in him… Therefore he said, "I will stretch forth my hand to the most high God, who made heaven and earth" (Gn 14,22).