106 - It was narrated that ‘Ali said: The Prophet (blessings and peace of Allah be upon him) said: “Do not tell lies about me; whoever tells lies about me, let him enter the Fire.”.

Commentary : In this hadith, the Prophet (blessings and peace of Allah be upon him) warns against telling lies about him, or attributing to him any words that he did not utter, or saying about him anything other than what really happened. So it should not be said that the Messenger of Allah (blessings and peace of Allah be upon him) said or did anything that he did not say or do, regardless of whether that is done with a bad intention or a good intention. This prohibition is general and applies to anyone who tells lies, because telling lies about him leads to introducing changes to Islamic teachings, and altering Islamic rulings. The punishment for the one who tells lies about him deliberately is admittance to Hell. Once a divine decree has been issued concerning something, it will inevitably happen and will definitely come to pass. This is a stern warning to anyone who tells lies about the Prophet (blessings and peace of Allah be upon him).
It was said that there is no difference between telling lies against him or telling lies for him, because what is meant by telling lies about him is attributing something to him that is not true, whether it is done with the intention of undermining his message or of supporting his message. Telling lies against Allah comes under the same heading and is telling lies about the Prophet (blessings and peace of Allah be upon him), because the aim of telling lies against Him is to tell lies with regard to the rulings of religion.
This hadith is indicative of the emphatic prohibition on telling lies about the Prophet (blessings and peace of Allah be upon him).
It indicates that whoever narrates a hadith knowing or thinking that it is fabricated is included in this warning, unless he explains the status of the narrators and how weak they are. Similar to that is one who rejects a sahih (sound) hadith that was narrated from the Prophet (blessings and peace of Allah be upon him) without having any knowledge of the science of hadith, or his reason for rejecting the hadith is stubbornness towards the teachings and rulings of Islam..