Prophet Muhammad named his grandsons Hassan and Hussein

'Ali said, "When al-Hassan was born, I named him Harb (war). The Prophet came and said, 'Show me your son. What have you named him?' 'Harb,' we replied. He said, "He is Hassan.' When al-Hussein was born, I named him Harb. The Prophet, May Allah bless him and grant him peace, came and said, 'Show me your son. What have you named him?' 'Harb,' we replied. He said, "He is Hussein.' When we had a third son, I named him Harb. The Prophet, May Allah bless him and grant him peace, came and said, 'Show me your son. What have you named him?' 'Harb,' we replied. He said, "He is Mohsin." Then he said, 'I have named them according to the names of the sons of Harun:

Shabr,  Shubayr, and Mushabbir.'"

Al-Adab Al-Mufrad, Book of Names, hadith: 823

Prophet Muhammad named his grandsons Hassan and Hussein

Prophet Muhammad named his grandsons Hassan and Hussein