In keeping with later teachings, God likely sacrificed a sheep or a lamb as a preview of the eventual sacrifice of the Lamb of God who would take away the sin of the world.
(yang / sheep, lamb, ram, ewe)
The Chinese characters have it perfectly correct, showing a lamb (yang / sheep, lamb) covering me (wo / me) gives me (yi / righteousness) in God's sight. Jesus Christ is that sheep (Lamb of God; John 1:29), sacrificed for us.
(yi / righteousness)
The character for (wo / me) has a hand and a spear at its
side. Perhaps that reflects the sinful nature of mankind - a killer.
(shou / hand)
(ge / spear)
(wo / me)
Jesus Christ's side was pierced by a spear to confirm his death. That was predicted a few hundred years earlier when the prophet Zechariah quoted God, saying "They will look on me, the one they have pierced..." (Zech. 12:10)
The simplified character for righteousness has no resemblance to the earlier characters. Yet the small line at the top is a drop of blood. The crossed lines can be either a sacrificial cup or firewood used for a burnt offering. The modern character still has a relationship to a sacrifice to purify us of our sins.
Take the character for a person: (ren / person).
Make him big (important?): (da / big).
Then cover him with the special sheep.
(mei / beautiful)
A similar character shows a big, noble person covered by the sheep (Lamb of God), thereby being beautiful in God's eyes.
Beginning, Oracle Bones, God, Water, Earth, Mankind, Adam, Eve, Good Tree, Bad Tree, Penalty, Clothes, Lamb, Gate, Murder, Flood, Lifespans, Scattering, Border Sacrifice, Genesis 1 to 11