The Messenger of Allah ﷺ said, "Hasan and Husayn are the masters of the youth of Paradise."
قال رسول الله ﷺ: الحسن والحسين سيدا شباب أهل الجنة.
Tirmidhi (3768), Ahmad (10999), and Nasai in Kubra (8474, 8473, 8472) all narrated it through different routes from Abdul-Rahman bin Abu Naim (he is the Bajali, from Kufah), from Abu Saeed Khudri, who said, and then he mentioned it. Its chain of transmission is hasan because of Abdul-Rahman bin Abu Naim, for his hadith is hasan. Tirmidhi said, "This is a hasan sahih hadith."