✅Answer: Ibn Shirawayh Daylami, one of the 'Umari' scholars, narrated it in the book Al-Firdaws, in the chapter Al-Alif wa Al-Lam, as follows:

عَنِ ابْنِ عَبَّاسٍ قَالَ (قَالَ رَسُولُ اللَّهِ صلی الله علیه و آله) : الْمَهْدِیُّ طَاوُسُ أَهْلِ الْجَنَّةِ.

📚Al-Firdaws, Vol. 4, p. 221

Translation: Ibn Abbas said: (The Prophet, peace be upon him and his family, said) The Mahdi is the peacock of the people of Paradise!

Ibn Batriq, also one of the 'Umari' scholars, narrated it in the book 📚Al-Umda, p. 439, hadith 922, from the book Al-Firdaws, and it has also been narrated from Al-Firdaws in some other miscellaneous 'Umari' books.

✅Unfortunately, this narration from the 'Umari' books has also found its way into some specific Shi'a books by certain Shi'a authors and is even exchanged among the Shi'a as banners and stickers!

✅However, as stated in the post (https://feghh14.com/en/1033), since this narration has not been transmitted through the infallible Imams (peace be upon them), it lacks the necessary authenticity for narration, publication, and belief and has no place for inclusion in the scholarly matters of the Shi'a concerning Imam al-Zaman, may Allah, the Exalted, hasten his reappearance.

اللَّهُمَّ صَلِّ عَلَی مُحَمَّدٍ وَ آلِ مُحَمَّدٍ وَ عَجِّلْ لِوَلِیِّکَ الْفَرَجَ وَ الْعَافِیَةَ وَ النَّصْرَ