Causes for differences in the features and traits of people

“We were with Amīr al-mu’minīn when discussion arose about the differences of men (in features and conduct) and then Amīr al-mu’minīn said”:

They differ among themselves because of the sources [1] of their clay (from which they have been created). This is because they are either from saltish soil or sweet soil or from rugged earth or soft earth. They,…