Hazrat Anas bin Malik (may Allah be pleased with him) narrates that the Noble Prophet (peace and blessings be upon him) said: "Some of my companions will be brought to me at the Pond, and I will recognize them, but then they will be taken away from me. I will say, 'These are my companions!' But it will be said to me, 'You do not know what new things they invented after you.'" (This refers to apostates, hypocrites, and innovators.)