Joshua 3:2 Midrash

וַיְהִ֕י מִקְצֵ֖ה שְׁלֹ֣שֶׁת יָמִ֑ים וַיַּעַבְר֥וּ הַשֹּׁטְרִ֖ים בְּקֶ֥רֶב הַֽמַּחֲנֶֽה׃

And it came to pass after three days, that the officers went through the midst of the camp;