Three days’ journey - Probably a technical expression for such a distance as could not be traversed in a single day, and therefore not without intervals of encampment and due provision: compare Genesis 30:36; Exodus 3:18; Exodus 5:3; Exodus 8:27; Exodus 15:22. The technical use of the phrase “Sabbath-day’s journey” for another average distance, Acts 1:12, is similar.
The ark of the covenant of the Lord went before them - From Numbers 10:21; Numbers 2:17 it would appear that the usual place of the ark during the march was in the midst of the host. It was evidently an exceptional case when, in Joshua 3:3, Joshua 3:6, the ark preceded the people into the bed of the Jordan. Hence, the words “went before them” do not here imply local precedence. The phrase, or its equivalent, is used of a leader going out in command of his troops, Numbers 27:17; Deu 31:3; 1 Samuel 18:16; 2 Chronicles 1:10; and similarly the ark may well be said to have gone at the head of the Israelites, when it was borne solemnly in the midst of them as the outward embodiment of the presence whose sovereign word was their law.
A resting place - literally, “rest.” It is commonly understood of each successive encampment; or, in particular, of the first encampment. Yet the term would hardly be here employed, did it not carry with it a higher meaning, pointing to the promised rest of Canaan, for which the Israelites were now in full march, and from the speedy enjoyment of which no sentence of exclusion as yet debarred them. Compare the marginal references.