The virtue of Hassan (may Allah be pleased with him)

It is narrated from Sa'id bin Jubayr (may Allah have mercy on him) that a man came to Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) and (speaking insolently of Sayyiduna Hassan bin Thabit (may Allah be pleased with him)) said: "That accursed Hassan has come." So Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) said (firmly rebutting him): "He is by no means accursed; he strove in jihad alongside the Messenger of Allah (peace and blessings be upon him) with his tongue and with his life."
Imam Abu Ya'la (may Allah have mercy on him) narrated this hadith in his Musnad, and its narrators are thiqat (trustworthy).

Habib bin Abi Thabit relates that Sayyiduna Hassan bin Thabit (may Allah be pleased with him) recited some verses of poetry before the Prophet (peace and blessings be upon him), saying: "I bear witness, by the leave and enabling of Allah, that Muhammad (peace and blessings be upon him) is the Messenger of the One who is above the lofty heavens, in the utmost height"; "And that Abu Yahya (Zakariyya, peace be upon him) and Yahya (peace be upon him), both of them are chosen souls whose deeds in their religion are accepted by Allah"; "And indeed the mention of the brother of the people of al-Ahqaf (Hud, peace be upon him) is also true: when he stood among his people to call them to the truth, he spoke among them of the Oneness of Allah and spoke with justice and fairness." Upon hearing this, the Prophet (peace and blessings be upon him) said: "And I too (bear witness to this)."
This hadith is sahih al-isnad (authentic in chain), though Imam al-Bukhari and Imam Muslim (may Allah have mercy on them both) did not narrate it (in these words) in their books.