Majma al-Zawaid — Hadith 15185

Sulayman bin al-Haytham says: Imam Zayn al-Abidin (may Allah be pleased with him) was performing tawaf of the House of Allah. When he intended to touch the Black Stone, the people made way for him. The poet named al-Farazdaq was watching this scene. A man said: O Abu Firas! Who is this? So al-Farazdaq recited these verses: "This is the one whose footstep the valley of al-Batha recognises; the House of Allah, the Hill and the Haram (regions) know him. This is the son of the best of all the servants of Allah Almighty. He is God-fearing, pure, clean and distinguished. When he touches it, the corner of the Hatim may well hold on to him, recognising his palm. When Quraysh saw him, one of them said: At his generosity, generosity reaches its end. He keeps his gaze lowered out of modesty, and out of awe of him the gazes of others are lowered (before him), so he is spoken to only when he smiles. In his hand is a staff of khayzuran (cane); his fragrance is excellent, and the scent of his palm spreads everywhere. He has derived his qualities from the Prophet (peace and blessings be upon him); his origins and his nature are pure. No swift runner can reach their station, and no people, however honoured they may be, can come near them. Which tribe is there that does not bear on its neck the collar of their precedence and their favour?"
Imam al-Tabarani recorded this narration, and its chain contains a narrator whom I do not know.