I was cutting some frozen butter with my milk knife. I slipped and cut into my finger. Some of the blood got on the butter. I threw the butter away, and put the knife into boiling water, but it was not a parve pot. I am so confused. What do you recommend?
I am sorry to hear about this accident.
Regarding your question, in retrospect, there was no need to throw out the butter, you could have just wash off the blood and the rest would have been fine. The reason for this is because human blood is not integrally forbidden to eat, it is only forbidden because of maris ayin, because it looks like blood. Therefore once the blood was removed from the butter the rest would have been permitted to eat.
Regarding the knife, the same rule would apply, that the knife did not need kashering, because any absorbed residue of blood in the knife would not be prohibited from eating.
Regarding the fact that you did kasher the knife, so we have to look at it as a milchig knife that was kashered. If you put the knife into a milchig or pareve pot, and the knife was clean, then everything is fine. The only concern would be on the unexpected chance that you kashered the knife in a fleishig pot that was used within the last 24 hours. If that was the case then you have to re-kasher the knife after waiting 24 hours, since the knife was milchigs. However I would assume that that is not what happened, therefore everything is fine… and I hope you finger is also…