Before the ark; as it were at the sight and approach of the ark, to give it and the Israelites a safe passage.
Related Commentaries of Joshua 4:7
Joshua 4:7
7 Then ye shall answer them, That the waters of Jordan were cut off before the ark of the covenant of the LORD; when it passed over Jordan, the waters of Jordan were cut off: and these stones shall be for a memorial unto the children of Israel for ever.