Breaking A Middah

לזכות שמואל אלכסנדר בן נעכא גיטל שיהיה כאחד הגדולים אשר בארץ

The gemara says that if one can help an enemy load his donkey or help a friend unload his donkey he should help his enemy load. This is surprising because helping unload the donkey is a fulfillment of decreasing the suffering of an animal which is a biblical commandment [צער בעלי חיים]. Despite this, he must help his enemy in order to break this feeling of hatred [לכוף את יצרו]. We see from here that working on one's middos overrides a biblical mitzva.

הגר"א גנחובסקי זצ"ל