He entered the city unexpectedly, without being noticed by the people. He found in it two men who were fighting, one was from his own race, and the other was from his enemy's. So the one who was from his own race called on him for help against his enemy, whereby Moses punched him, killing him. He said, "This is from the work of the devil; he is an enemy that clearly misleads."
Translation endnotes
[28:15] Moses attributes this event to devil, since he acted with racist emotions by trusting the account of his tribesman without cross examining him or without questioning the other party about the issue. This is a common crime we tend to commit frequently. We make judgment about other people by just listening one party. If a wise man like Moses (28:14; 26:21) fall into the trap of tribalism and racism, we should investigate thoroughly before siding with one party against the other. We are expected to side with justice, even if against us and our family members. (See also: 38:24 and 4:135).