And he said,
Take now thy son, thine only son Isaac,
whom thou lovest,
and get thee into the land of Moriah;
and offer him there for a burnt offering upon one of the mountains
which I will tell thee of.
Genesis 2:22
And lo a voice from heaven, saying,
This is my beloved Son,
in whom I am well pleased.
Matthew 3:17
First reference of "Love" in the Old Testament is about the love of a father (Abraham) for a son (Isaac). In the New Testament the first mention of "Love" is the Father above for His Son who was sent here below.
Also, note that in both cases the son/Son was willing to go to the altar of sacrifice in obedience to God.