Malik related to me that Safwan ibn Sulaym said, "The Messengerof Allah, may Allah bless him and grant him peace, was asked, 'Can themumin be a coward?' He said, 'Yes.' He was asked, 'Can the mumin be amiser?' He said, 'Yes.' He was asked, 'Can the mumin be a liar?' Hesaid, 'No.' " (PT)
USC-MSA web (English) reference: Book 56, Hadith 19 (PT)
Arabic reference (PT): Book 56, Hadith 1832 (PT)