To the mountain, i.e. to some of the mountains wherewith Jericho was encompassed, in which also there were many caves where they might lurk. Three days; not three whole days, but one whole day, and parts of two days: See Poole on "Joshua 1:11".
Related Commentaries of Joshua 2:16
Joshua 2:16
16 And she said unto them, Get you to the mountain, lest the pursuers meet you; and hide yourselves there three days, until the pursuers be returned: and afterward may ye go your way.