הלכה על מועד קטן 54:1

It is from the roots of the commandment [that it is] in order that we not do amongst ourselves any matter at all that is similar to the worshipers of idolatry, and like the matter that I wrote in the negative commandment of encircling the head in the Order of Kedoshim Tehiyu (Sefer HaChinukh 251). And we have been prevented from gashing over the dead, as it is not proper for the chosen people - those of the wisdom of the precious Torah - to pain themselves about something from the creation of God, except for the matter through which He, blessed be He, commanded us to pain ourselves, and for the reason that I wrote in the Order of Emor el HaKohanim in the first commandment (Sefer HaChinukh 264). But that we should destroy our bodies and disfigure ourselves like fools is not good for us. And it is not the way of sages and men of understanding, but rather an act of the masses of lowly women that lack intellect, that have not understood anything from the creation of God and His wonders. And Ramban, may his memory be blessed, wrote (Ramban on Deuteronomy 14:1) [that] from here, there is a support for our Rabbis, may their memory be blessed, in their forbidding mourning for the dead more than is enough (Moed Katan 27b).