Malik related to me that Safwan ibn Sulaym said, "The Messenger
of Allah, may Allah bless him and grant him peace, was asked, 'Can the
mumin be a coward?' He said, 'Yes.' He was asked, 'Can the mumin be a
miser?' He said, 'Yes.' He was asked, 'Can the mumin be a liar?' He
said, 'No.' "
Muwatta Malik Book 56, Hadith 19