This is the Torah: when a man dies in a tent, all who come into the tent and all that is in the tent shall be unclean seven days.
Torah Temimah: Yevamos 61a — Rabbi Shimon ben Yochai says: The graves of idolaters do not convey tent-impurity, for it is written “a man who dies in a tent” and it is written (Yechezkel 34:31) “and you are My flock, the flock of My pasture; you are adam” — you are called adam, and idolaters are not called adam.
English: Rabbi Shimon ben Yochai says: The graves of idolaters do not convey tent-impurity, for it is written “a man who dies in a tent” and it is written “you are adam” — you are called adam, and idolaters are not called adam.
Restriction of the term “adam” to Yisrael for this impurity.
According to this view, the tent-impurity of a corpse applies only to the body of a Jew; the graves of non-Jews do not generate tent-impurity.