The preparations for crossing the Jordan River reach their final stages, and the leadership shifts from a period of waiting to direct action. A designated three-day timeframe marks the conclusion of the period previously set by Joshua, when he instructed the Israelites to prepare provisions for their journey into the land [מצודת דוד, ביאור שטיינזלץ].
To understand the exact timeline of these events, it is necessary to look back to the passing of Moses, which occurred on the seventh of Adar. Following his death, the people observed thirty days of mourning. Because divine inspiration does not rest upon a person who is in a state of sadness and mourning, God only revealed Himself to Joshua to command the crossing on the seventh of Nisan, immediately after the mourning period ended. On that very day, Joshua instructed the people to prepare for a crossing that would take place in three days. In the meantime, the spies whom Joshua had sent out while the people were still mourning returned the following day, the eighth of Nisan [רד״ק].
There are different approaches regarding the exact target date of this three-day period. One perspective suggests it refers to the tenth of Nisan, the actual day the Israelites crossed the Jordan, serving as the culmination of their three days of preparation [רד״ק]. Another approach understands this as the ninth of Nisan, the end of the third day itself. According to this view, the Israelites traveled from Shittim to the banks of the Jordan River on the ninth, and the officers went through the camp to ready the people for the miracle that would take place the following morning [מלבי״ם, ביאור שטיינזלץ, רד״ק].
A careful calculation of this timeline—factoring in the days of mourning and the journey leading up to the conquest of Jericho, which fell on the Sabbath—resolves a historical question regarding the exact timing of Moses' passing. Tracing the chain of events backward from the day they crossed the Jordan proves that his death could not have occurred on a Sabbath afternoon [רד״ק].