A similar wording was related by Ibn Sīrīn from him, and there are a number of ḥadiths on the point, so the report is mass-transmitted (mutawātir).
Abū Bakrah said, “I saw the Messenger of Allah ﷺ on the pulpit with Ḥasan standing beside him, and he was saying, ‘This son of mine is a leader, and perhaps Allah will bring reconciliation through him between two groups of Muslims.’ (1)
Yazīd ibn Abī Ziyād narrates—from ʿAbd al-Raḥmān ibn Abī Nuʿm, from Abū Saʿīd—in a Prophetic report: ‘Ḥasan and Ḥusayn are the chiefs of the youth of Paradise.’
al-Tirmidhī declared it authentic. (2)
al-Tirmidhī also graded as sound the ḥadith of Usāmah ibn Zayd, who said:
“The Messenger of Allah ﷺ came out one night wrapped in something.
I asked, ‘What is this?’
He uncovered it, and there were Ḥasan and Ḥusayn on his hips. He then said, ‘These are my two sons—the sons of my daughter. O Allah, I love them, so love them and love whoever loves them.’ (3)
(1) Reported by al-Bukhari, 7/74, in “The Merits of the Companions,” chapter “The Virtues of al-Hasan and al-Husayn”; also in “Reconciliation,” chapter “The Prophet’s statement about al-Hasan: ‘This son of mine is a leader …’ ”; in “The Prophets,” chapter “Signs of Prophethood in Islam”; and in “Manumission,” chapter “The Prophet’s statement about al-Hasan: ‘This son of mine is indeed a leader.’ ” Also transmitted by al-Tirmidhi (no. 3775), al-Nasa’i 3/107, Abu Dawud (no. 4662), al-Tabarani (nos. 2588, 2592, 2593), and Ahmad 5/38, 44, 49, 51.
(2) Listed by al-Tirmidhi under no. 3768; likewise narrated by Ahmad 3/3, 62, 44, 84; al-Tabarani (nos. 2610, 2612); Abu Nuaym 5/71; al-Khatib 4/207 and 11/90; al-Hakim 3/166–167; and al-Fasawi in his “History” 2/644, all through the chain of Abd al-Rahman ibn Abi Nu‘m from Abu Sa‘id. The hadith is authentic, for it is supported by many corroborations: from Hudhayfa (with a sound isnad, to be cited by the author on p. 252, note 3); from Abd Allah ibn Masud, recorded by al-Hakim 3/167 and judged sound by him, a verdict endorsed by al-Dhahabi; from Usama ibn Zayd at al-Tabarani (no. 2618); from Jabir ibn Abd Allah at Ibn Hibban (no. 2236); from Ali at al-Khatib al-Baghdadi 1/140 and al-Tabarani; from Umar at Abu Nuaym 4/139–140; and from Qurra ibn Iyas, Malik ibn al-Huwayrith, al-Husayn ibn Ali, and al-Bara ibn Azib. See Majma al-Zawaid 9/182.
(3) Reported by al-Tirmidhi (no. 3769).