Sahih Adab al-Mufrad

It is narrated from Awsat bin Ismail that he said: After the death of the Prophet (peace be upon him), I heard Sayyiduna Abu Bakr (may Allah be pleased with him) say: In the first year of Hijrah, the Prophet (peace be upon him) stood at the very place where I am standing now. Saying this, Sayyiduna Abu Bakr (may Allah be pleased with him) began to weep, and then said: Adhere to truthfulness, for it is with righteousness, and both are in Paradise. And beware of lying, for it is with wickedness, and both are in Hell. And ask Allah for well-being, for after certainty, there is nothing better given to a person than well-being. And do not sever ties with one another, nor boycott one another, nor envy one another, nor bear malice against one another, and be, O servants of Allah, brothers to one another.

Narrated from Sayyiduna Abbas bin Abdul Muttalib (may Allah be pleased with him) that he said: I submitted, "O Messenger of Allah! Teach me a supplication by which I may ask Allah." The Prophet (peace and blessings be upon him) said: "O Abbas! Ask Allah for well-being." Then he remained silent for three days. Then I came and said: "O Messenger of Allah! Teach me something by which I may ask Allah." So the Prophet (peace and blessings be upon him) said: "O Abbas! O uncle of the Messenger of Allah! Ask Allah for well-being in this world and the Hereafter."