And it is narrated from him that 'Umar (may Allah be pleased with him) passed by Hassan reciting poetry in the mosque, so he glanced at him, and he said: "I used to recite in it, and there is in it someone better than you." Agreed upon by al-Bukhari and Muslim.

The Shaykh : We are taking a new lesson. He said: "And it is narrated from him" — meaning from Abu Hurayrah (may Allah be pleased with him) — "

Umar came over Hassan while reciting poetry inside the mosque and looked at him sternly, then he (Hassan) said: "I used to recite poetry inside it (the mosque) in the presence of one who is more pious than you

أن عمر رضي الله عنه مر بحسان ينشد في المسجد، فنظر إليه، فقال: قد كنت أنشد فيه وفيه من هو خير منك

Bulugh al-Maram 2:127

. Agreed upon by al-Bukhari and Muslim." It is said that 'Umar ibn al-Khattab (may Allah be pleased with him), the Commander of the Faithful, passed by Hassan ibn Thabit, the most famous of the poets of the Prophet (peace and blessings be upon him and his family) and the one who composed the most poetry about the Prophet (peace and blessings be upon him) and his Companions, and he is the famous poet.
It is said meaning he recites his poems. Is it with singing or not? We say that it is not required to be with singing; reciting poetry is delivering the poem, whether it is with singing or without singing.
Meaning he looked at him with a hidden look, as if criticizing him, so Hassan (may Allah be pleased with him) understood that and said: meaning in the mosque, meaning the Messenger of Allah (peace and blessings be upon him and his family). The meaning of the hadith is clear: Hassan (may Allah be pleased with him) was reciting poetry in the mosque, so when 'Umar (may Allah be pleased with him) saw him looking at him with a look of disapproval, he responded and defended himself because he was in ... the Messenger of Allah (peace and blessings be upon him and his family).