(Is he who is a believer like unto him who is an evil-liver?) [32:18].
This verse was revealed about ‘Ali ibn Abi Talib and al-Walid ibn ‘Uqbah.
Abu Bakr Ahmad ibn Muhammad al-Asfahani informed us> ‘Abd Allah ibn Muhammad al-Hafiz> Ishaq ibn Banan al-Anmati> Hubaysh ibn Mubashshir al-Faqih> ‘Ubayd Allah ibn Musa> Ibn Abi Layla> al-Hakam> Sa‘id ibn Jubayr> Ibn ‘Abbas who said: “Al-Walid ibn ‘Uqbah ibn Abi Mu‘ayt said to ‘Ali ibn Abi Talib, may Allah be well pleased with him: ‘I am tougher than you, more eloquent than you, and I have more leadership skills than you’. ‘Ali responded by saying: ‘Be quiet, you are but an evil-liver!’ This verse was then revealed (Is he who is a believer like unto him who is an evil-liver? They are not alike), by the believer is meant ‘Ali ibn Abi Talib and the evil-liver refers to al-Walid ibn ‘Uqbah”.
Asbab Al-Nuzul by Al-Wahidi , trans. Mokrane Guezzou