Joshua 5

1 Their hearts melted because they knew that their destruction was imminent, and they recognized that God was capable of doing what He had promised to do for the Israelites. God had given the people of the land over 400 years to repent. Now their time of judgement had come, and they would not escape it (Gen 15:13-16).
2 As God's representatives, the Israelites were to obey Him. God had told Abraham to circumcise himself and his household as a sign that he believed and followed God. This sign was to be passed down to his descendants. However, while wandering in the wilderness, the Israelites had not circumcised their male sons as had been ordained. However, God now demanded that they complete this act of obedience before they carried on further in His name. While we as Christians have been freed from the "burden" of obedience to this particular law, there are other areas of obedience that we need to follow: baptism, sexual purity, bearing witness of Jesus, aiding the poor, and others. We may neglect areas for some time, but there will come a point where we can not proceed further in our spiritual walk until we make one or more of these areas obedient to God.
5 It is not exactly clear why circumcision had not been performed in the wilderness. The wording makes it sound as though the Israelites had continued to perform circumcision while captives in Egypt but had ceased to do so when they left. I suppose it could be argued that the nomadic lifestyle of those forty years was not conducive to this surgical operation, but it must be remembered that at times the people would "camp" for a year before moving on (Num 9:22). It appears that the more likely reason was simply disobedience (probably enhanced by bitterness). The generation that left Egypt had proven to be stubborn and disobedient from the outset, and this continued throughout the wilderness. The symptom of disobedience here was the neglecting of the sign of their commitment to God. It is also not clear why Moses did not enforce this law since he knew firsthand that it was important (Exo 4:25).
8 This pause could have lasted two weeks to a month. During this time they were vulnerable to attack (remember Gen 34:25?). They were weak and would have been trapped with the river behind them. However, God was protecting them, and having the circumcision take place when it did showed great faith on the part of the Israelites.
9 The "reproach" of Egypt could mean several things. The most significant would be that Egypt would have to acknowledge that God had indeed removed Israel from that land and had placed them in the land He had promised Abraham.
10 It appears that the Israelites had not celebrated the Passover since their first year out of Egypt (Num 9:2, Num 28:16). Although Moses had written down the laws about the Passover, they apparently remain unobserved until now (Exo 12:43-50).
11 The conquest had started. The Israelites were no doubt camped on or near cultivated land. The farmers had already fled into Jericho. It was previously mentioned that it was harvest time (Josh 3:15), so the Israelites were harvesting and eating food grown in the land.
12 God provided food for the Israelites from the land, thus it was no longer necessary to do so "supernaturally." The Israelites would now have to work to get food. There may be times in our lives when God provides for us, but usually He provides the opportunities for us to work for our provisions. We should not see our working opportunities as any less of a provision from God than if He simply delivered the food to our doors. God made us to work (Gen 2:15), and here God is returning Israel to a working lifestyle.
13 Joshua shows extreme confidence to approach the man with the drawn sword. God had assured Joshua that no one would defeat him if he were strong, courageous, and obedient. He was, unknowingly, approaching a theophany (physical incarnation) of God. He first issues a challenge question, but once he realizes that he is speaking to God, he immediately humbles himself.
14 Some people debate weather God will help one team beat another in a given competition. In almost every competition someone will win. Certainly in at least some competitions, God will aid one side to victory (as here with Israel). However, God is much bigger than any competition that might develop on earth. God's primary concern is that people come to know Him. Whether we are "winners," "losers," or "spectators" we are to bow down and worship God. Here Joshua humbles himself, asks for direction, and prepares himself to listen and obey.
15 This is similar to Moses' encounter with God at the burning bush (Exo 3:2-5).