It is narrated from Ubaid Kindi, may Allah have mercy on him, that I heard Sayyiduna Ali, may Allah be pleased with him, saying to Ibn Kawwa: Do you know what the people of old used to say? (He said:) When you love someone, do not go to extremes, for it is possible that the same person may become your enemy tomorrow. And when you have enmity with someone, do not go to extremes in your enmity either. It is possible that the same person may become your friend one day.