Dhi`lib Yamami related from Ahmad bin Qutaybah, and he from Abdullah bin Yazid and he from Malik bin Dihyah who said, "We were with Ameerul Momineen when discussion arose about the differences of men (in features and conduct) and then Imam said":

They differ among themselves because of the sources of their clay (of creation). This is because they are either from saltish or sweet soil or from rugged or soft earth. They resemble each other on the basis of affinity of their soil and differ according to its difference. Therefore, sometimes a person of handsome features is weak in intelligence, a tall statured person is of low courage, a virtuous person is ugly in appearance, a short statured person is far-sighted, a good-natured person has an evil trait, a person of perplexed heart has bewildering mind and a sharp-tongued person has a wakeful heart.