How did the Aron pass?
Rashi (citing a Midrash): It was unlike the people, rather, like it says below. The Kohanim's feet went back to the bank from which they entered, the river returned to flow, and the Aron carried them across. 1
Radak: Refer to 4:11:2:3.
Malbim: The Aron was by the eastern bank until now. Now it passed to the west bank.
Radak: If such a miracle occurred, why did the verses not say so? However, Chazal knew what they said; they know more than us.
What is the meaning of "Lifnei ha'Am"? (The people already passed!)
Rashi: It is in the eyes of the people.
Radak #1: The Aron and Kohanim were in front of the people before the people passed.
Radak #2: After the people passed, they waited on the bank of the Yarden until the Aron passed in front of the people, and they went in back of it.