Sunan Abi Dawud

Salam ibn Miskin, quoting an old man who witnessed AbuWa'il in a wedding feast, said:They began to play, amuse and sing. He united the support of his hand round his knees that were drawn up, and said: I heard Abdullah (ibn Mas'ud) say: I heard the apostle of Allah (ﷺ) say: Singing produces hypocrisy in the heart