Narrated Hudhaifa that he saw a person bowing and prostrating imperfectly. When he finished his Salat, Hudhaifa told him that he had not offered Salat. The subnarrator added, "I think that Hudhaifa also said:Were you to die you would die on a "Sunna" (legal way) other than that of Muhammad (ﷺ)

English translation · Sahih al-Bukhari