Musnad Ahmad 16:6

Yahya ibn Sa'id narrated to us, from Shu'bah, Burayd ibn Abi Maryam narrated to me, from Abu al-Hawra' al-Sa'di, who said: I said to al-Hasan ibn Ali: "What do you remember from the Messenger of Allah, may Allah bless him and grant him peace?" He said: "I remember that I took a date from the dates of the charity (sadaqah) and put it in my mouth. The Messenger of Allah, may Allah bless him and grant him peace, pulled it out with its saliva and threw it back into the dates." A man said to him: "What would it have mattered to you if he had eaten this date?" He said: "We do not eat charity." He said: And he used to say: "Leave what makes you doubt for what does not make you doubt, for truthfulness is tranquility, and lying is doubt." He said: And he used to teach us this supplication: "O Allah, guide me among those whom You have guided, grant me well-being among those whom You have granted well-being, take me into Your care among those whom You have taken into Your care, bless for me what You have given, and protect me from the evil of what You have decreed. For indeed, he whom You befriend is not humiliated." And sometimes he would say: "Blessed are You, our Lord, and Exalted."