"Abraham, Abraham!" So he said, "Here I am." And He said, "Do not lay your hand on the lad, or do anything to him..."
A painting on display at the Museum of Fine Arts at Seville, Spain depicting the Bible narration of Abraham's faith in God to sacrifice his son as offering to God and how Gad saved his son Issac by sending His Angel and providing a Lamb for his offering.
God told Abraham.. "Take now your son, your only son Isaac, whom you love...go to the land of Moriah, and offer him there as a burnt offering on one of the mountains" Gen 22.2
Issaac spoke to Abraham his father and said, "My father!" And he said, "Here I am, my son." Then he said, "Look, the fire and the wood, but where is the lamb for a burnt offering?"
Abraham said, "My son, God will provide Himself the lamb for a burnt offering." So the two of them went together. Gen 22.7
Acccording to Christian theology that lamb without blemish provided by God for Abraham's sacrifice saving his son is symbolic of Jesus Christ.
God spared Abraham's son from being sacrificed, but... Many centuries later, God did NOT spare His own Son. Instead, God delivered Him up to be crucified... for YOU. Although "The Father loves the Son [Jesus], and has given all things into His hand."
In Remembrance of that Love of God in giving His own son for sacrifice for saving the human race from sins on This Day..