Midrasch zu Wajikra 19:21

6) (Vayikra 19:21) "And he shall bring his guilt-offering to the L–rd, to the door of the tent of meeting, a ram for a guilt-offering." It is written here "a ram for a guilt-offering," and, elsewhere (Vayikra 5:15) "a ram .. for a guilt-offering. Just as there, with shekels of silver, here, too, with shekels of silver.