Rashi: [Yehoshua circumcised the children of Dor ha'Midbar] that Hashem established in place of them [Radak - to inherit Eretz Yisrael. It is as if it says she'Hekim. We find like this also elsewhere, e.g. "la'Am Aleha" (Yeshayah 42:5) is like la'Am she'Aleha.]