Joshua 3:5

“And Joshua said unto the people, etc.] On the third day; and the thirtieth day of the mourning for Moses, Jarchi says, was the first of the three days, and that being the seventh day of the month, this must be the ninth, as it is most clear the morrow was the tenth: sanctify yourselves; in a ceremonial sense, by washing their bodies and their clothes, and abstaining from their wives; and in a moral sense, by acts of religion and devotion, by prayer and meditation, and the exercise of repentance and, good works: it may denote that sanctification is necessary to our passage over Jordan, or through death to the heavenly Canaan, for without holiness no man shall see the Lord: for tomorrow the…”

“Joshua said unto the people--rather "had said," for as he speaks of "to-morrow," the address must have been made previous to the day of crossing, and the sanctification was in all probability the same as Moses had commanded before the giving of the law, consisting of an outward cleansing (Exo 19:10-15) preparatory to that serious and devout state of mind with which so great a manifestation should be witnessed.”

“And Joshua said - Or rather, had said, the day before their passage; for it follows, to - morrow. Sanctify yourselves - Both in soul and body, that you may be meet to receive such a favour, and with more reverence observe this great work, and fix it in your hearts. Joshua 3:6”

“3:5 Purify yourselves: They had to separate themselves from anything unclean that would bar an Israelite from coming into God’s presence (cp. Exod 19:9-20; Lev 11:44).”

“Sanctify: Jos 7:13; Exo 19:10-15; Lev 10:3, Lev 20:7; Num 11:8; Sa1 16:5; Job 1:5; Joe 2:16; Joh 17:19 the Lord: Jos 3:13, Jos 3:15; Psa 86:10, Psa 114:1-7 Joshua 3:6”