Hawzah News Agency – The commander of the faithful, Imam Ali peace be upon him says:

إيّاكُم والمِراءَ والخُصومَةَ؛ فإنّهُما يُمرِضانِ القُلوبَ علَى الإخوانِ، ويَنبُتُ علَيهما النِّفاقُ.

'Beware of disputation and argument, for they sicken the hearts against brothers, and hypocrisy grows from them.'

Source: al-Kafi, v. 2, p. 300, no. 1