Sahih Muslim Book 45, Hadith 112

Allah's Messenger, the good would reach everyone but it would not reach these two. He said: Why so? I said: Because you have invoked curse and hurled malediction upon both of them. He said: Don't you know that I have made condition with my Lord saying thus: O Allah, I am a human being and that for a Muslim upon whom I invoke curse or hurl malediction make it a source of purity and reward.

Previous Hadith

Invoke curse upon the polytheists, whereupon he said: I have not been sent as the invoker of curse, but I have been sent as mercy."

Sahih Muslim Book 45, Hadith 111
Next Hadith

" He had a private meeting with them and hurled malediction upon them and cursed them and sent them out."

Sahih Muslim Book 45, Hadith 113