Majma al-Zawaid — Hadith 10457

Yazid bin al-Asamm narrates: I went out with Sayyiduna Hasan (may Allah be pleased with him), and at that time a slave girl was scraping some henna from his nails. A bundle of letters came to him, and he said: "O girl, bring the large basin and pour water into it." Then he had the letters put into the water. He did not open any of them, nor did he look at them. I said: "O Abu Muhammad, from whom are these letters?" He replied: "From the people of Iraq. They are people who do not return to the truth and do not hold back from falsehood. I do not fear them for myself, but I fear them for this one." Imam Hasan said this while pointing towards Imam Husayn.
Al-Tabarani recorded it, and its narrators are the narrators of the Sahih except Abdullah bin al-Hakam bin Abi Ziyad, and he is thiqah (trustworthy).