Sayyiduna Jabir (may Allah be pleased with him) narrates: The Prophet (peace and blessings be upon him) saw a man whose hair was dishevelled. He said: "Why does one of you disfigure himself?" The Prophet (peace and blessings be upon him) gestured to him with his blessed hand, meaning: cut it.
Al-Tabarani recorded it in al-Mu'jam al-Awsat from his teacher Musa bin Zakariyya al-Tustari, and he is da'if (weak).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب اللباس / 8829