I googled it because it sounded familiar; [book of revelations (https://www.gotquestions.org/Jesus-hair-like-wool.html) (i.e the bibles "Epilogue"!)

Since he's dead and this is a vision, I think they were actually trying to depict him as literally being a sheep in this passage. His hair is not just wooly but white, too.

Jesus was compared to a lamb so often because jewish tradition had lambs slaughtered on passover, for eating. He is "the sacrificial lamb" - Jesus's crucifixion was seen as him sacrificing himself on passover, if I understand correctly. I only mention this because it's one of the interesting elements of the religion that people don't fully understand the significance of because its actually rooted in the existing Jewish traditions.