Dvar Torah by Rabbi Zelig Pliskin
The Torah states, “And Moshe went out to meet his father-in-law, and he bowed down, and kissed him; and they asked each other of their welfare” (Exodus 18:7). Moshe’s wife and sons were also coming to him. Why does Moshe make a point out of greeting his father-in-law first?
Comments Rabbi Naftoli Tzvi Berlin in Haamek Dovor, Moshe greeted his father-in-law first because of the obligation to honour one’s in-laws. The Pele Yoatz writes that a son-in-law (or daughter-in-law) should appreciate the fact that his parents-in-law spent much time and effort in raising their child who is now his wife (or her husband). In gratitude, a person should always treat his in-laws with the proper respect!