Abu Hurayrah (may Allah be pleased with him) reported that the Prophet (may Allah's peace and blessings be upon him) said: "Anyone who loves Al-Hasan and Al-Husayn has indeed loved me, and anyone who hates them has indeed hated me.”
Authentic hadith - Narrated by Ibn Majah - Narrated by Ahmad
This Hadīth indicates the high status of Al-Hasan and Al-Husayn, the Prophet's grandsons. Anyone who loves them has indeed loved the Prophet (may Allah's peace and blessings be upon him) and anyone who hates them has actually hated the Prophet.