Narrated Anas bin Malik: Allah's Apostle mentioned the greatest sins or he was asked about the greatest sins. He said, To join partners in worship with Allah; to kill a soul which Allah has forbidden to kill; and to be undutiful or unkind to one's parents. The Prophet added, Shall I inform you of the biggest of the great sins? That is the forged statement or the false witness. Shu`ba (the sub-narrator) states that most probably the Prophet said, the false witness.