'Atiya as-Sa'di reported God's Messenger as saying, "No one will attain to being one of the pious till he abandons things which are harmless through being on his guard against what is harmful."
Wabisa b. Ma'bad reported God’s Messenger as saying, “Have you come to ask about righteousness and sin, Wabisa?” When he replied that he had, he joined his fingers and striking his breast with them said, “Ask yourself for a decision, ask your heart for a decision (saying it three times). Righteousness is that with which the soul is tranquil and the heart is tranquil, but sin is that which rouses suspicion in the soul and is perplexing in the breast, even if people give you a decision in its favour.”
Narrated Anas said that God’s Messenger cursed ten people in connection with wine:
the wine-presser, the one who has it pressed, the one who drinks it, the one who conveys it, the one to whom it is conveyed, the one who serves it, the one who sells it, the one who benefits from the price paid for it, the one who buys it, and the one for whom it is bought.
I have retained in my memory these words of God's Messenger, “Leave what causes you doubt and turn to what does not cause you doubt. Truth is tranquility, but falsehood is doubt.”
Ahmad, Tirmidhi and Nasa’i transmitted it, and Darimi transmitted the first part.