Charles Ellicott Commentary Joshua 3:16

"that the waters which came down from above stood, and rose up in one heap, a great way off, at Adam, the city that is beside Zarethan; and those that went down toward the sea of the Arabah, even the Salt Sea, were wholly cut off: and the people passed over right against Jericho." — Joshua 3:16 (ASV)

Very far from the city Adam, that is beside Zaretan. —The written text is “in Adam,” but the Masorites read it “from Adam.” The reading makes no difference to the literal fact. The two prepositions, in and from, express the same thought. The heap of water stood up as it were in Adam. From Adam to the place where Israel crossed, the river-bed was dry—the heap was as far away as Adam, but as it was not actually in the city, the word in was most likely altered to from.