I heard the Prophet ﷺ say, "Whoever lies about me deliberately, let him take his seat in the Fire."
حدثنا هاشم حدثنا عيسى بن طهمان قال
سمعت النبي ﷺ يقول من كذب علي متعمدا فليتبوأ مقعده من النار
Its isnad is sahih, mentioned previously at 13905.