Hakhel and the writing of a Torah are commandments that stress the unity of the Jewish people. Hakhel encompasses all Jews — “men, women, children and proselytes” — equally. Indeed, that is why this commandment is termed Hakhel, which means “congregation.” In this case, those who congregate lose their individual identity and form an entirely new totality.
Writing a Torah scroll, too, stresses the concept of unity, for while Jews differ greatly in their comprehension of Torah, all are equal with regard to writing a Torah scroll.