He’s just pointing out that God made that sacrifice for us. It was foreshadowed when he told Abraham to sacrifice his “only begotten son” Isaac (though he had 8; but the first was born in sin from a maid because he and his wife lacked faith that she could get pregnant, and ultimately fathered the Arab nations; the second was the child God promised him; and 6 came with a later wife after Sarah died). It was also shown, in a way, to Moses when he had to build the tabernacle and start the sacrifices for Israel’s sins. That was more about unraveling how the heavenly sanctuary would operate once Jesus’ blood would be sprinkled on the mercy seat and his garments to begin his ministry; but it still eluded to his imminent sacrifice for the sins of man. He wants us to be fruitful and multiply. He made this world for us. The twisted world tries to convince people that having children is selfish and somehow bad for the environment. It’s always the opposite. We can never reach Gods level in anything, so we just try to learn from the scriptures and apply them as best as we can.