a'ishah, with whom allah is pleased, said:

'the prophet, may allah exalt his mention, was not given a choice between two matters, except that he chose the easier of the two, as long as it was not a sinful act. if that act was a sinful act, he would be the farthest from it. by allah! he never avenged himself. he only became angry when people transgressed the limits and boundaries of allah; in that case he avenged.'  (bukhari #6404)