By my count, this would be God’s third named and documented curse in Genesis. The serpent (Gen 3:14) and Adam (Gen 3:17) are very specifically “cursed,” but Eve’s punishment was not described as a “curse,” although surely it was one. Anyway, here Cain is cursed in a way similar to Adam: the ground is cursed even more, and he is sent even farther away from God’s presence.