Was the Prophet, peace and blessings be upon him, continuously sorrowful?

This sentence is part of a long hadith (definition) narrated by Al-Tabarani and Ibn Abi Hatim, which was weakened by Ibn al-Qayyim and Ibn Taymiyyah. Ibn al-Qayyim mentioned that the hadith is not authentic, and its chain of transmission includes unknown narrators. He also stated that the Prophet was not perpetually sorrowful; rather, he was always cheerful and smiling. As for Ibn Taymiyyah, he clarified that the forbidden sorrow is the pain over the loss of something desired or the occurrence of something disliked, and that what was reported in the description of the Prophet is not this type, but rather it is attention and vigilance regarding future matters.