Aaron, Moses’ brother, was a master at making peace between people. He had intense love for everyone, and with this great love he was able to motivate other people to love each other. Flames of love came from his heart, and this entered the hearts of everyone else.
Today, think of two people you know who need to make peace, and use Aaron as a model.
Sources: see Rabbi Chaim Zaitchyk – Maayanai Hachaim, vol.3, p.190; Rabbi Zelig Pliskin’s “Consulting the Wise”