Protoevangelium - A term (based on the Greek words for “first” [protos] and “gospel” [evangelion]) that refers to the first allusion to the gospel in Gen 3:15, where God promises that Eve’s offspring will prevail over the serpent’s offspring.
Genesis 3:15 CSB
I will put hostility between you and the woman, and between your offspring and her offspring. He will strike your head, and you will strike his heel.