The severity of telling lies about the Messenger (sallal-laahu-alayhi-wasallam)
The Messenger (sallal-laahu-alayhi-wasallam) said: ”Whoever tells lies about me intentionally then let him take his place in hell.’’
Al-Haafidh Ibn Hajar (rahimahullaah) said: The wisdom behind the severity of telling lies against the Prophet (sallal-laahu-alayhi-wasallam) is clear, for indeed he transmits information from Allaah (The Most High). So whoever lies against him has lied against Allaah….
[For further details see: Dawaabit Ar-Riwaayah Indal Muhadditheen Vol 1 page 134 by Shaikh Raslaan (may Allaah preserve him)]