Today's reading contains much foreshadowing of future events.  There are several connections to the fall of Jericho in the book of Joshua and the fall of evil on earth as recorded in the book of Revelation.  As recorded in Joshua 6, there are seven priests who carry seven trumpets in front of the ark.  On the seventh day, they march seven times around the city of Jericho. The people were to remain quiet until told to shout. On the seventh day on the seventh time around the city the people shouted as the seven priests blew the trumpets.  Then the walls of the city fell.  As recorded in Revelation 8 there is silence in heaven for about half an hour. There were seven angels.  One of the angels sent to the earth thunder, lightning and an earthquake.  Then the seven angles who had the seven trumpets prepared to sound them.

The battle of Jericho is a foreshadowing of the beginning of the coming Millennium, the multiple "sevens" in Jericho and the multiple "sevens" in Revelation's seven seals. Even the point of the destruction of Jericho is a symbol of the destruction of evil on earth prior to the Millennium.  The walls of Jericho fell.  The Israelites went into the city, killed every living thing, and burned the remnants of the city, except for those who were protected (Rahab and her family).  They were brought out alive to live with the Israelites.  The prophecies about the beginning of the Millennium are very similar.  God's people will enter into their "places of safety" (Isaiah 26:20-21). Every other living thing on earth will be killed.  The face of the earth will be burned and only God's people will survive.  They will come out and "leap like calves in the ashes" (Malachi 4:2-3) and  will live with God's people during the Millennium. Other connections can be found in 1 Thes 4:16. Rahab and her family were saved because of the scarlet rope.  Believers are saved because of the blood of Jesus.

When the Israelites took Jericho they were told to keep away from the devoted (or accursed) things within the city. These would be things that the people devoted to other gods. Yet Achan acts unfaithfully and takes some of the devoted things. His one act of disobedience brought about God’s anger against all Israel.
A lesson for us today…when we sin others almost always get hurt. Sin has consequences.

In Joshua 7, Joshua prays a prayer similar to one that Moses prayed.  At the time Joshua prayed, it seems as if he was unaware of the sin of Achan so he may have been confused about why God allowed the routing of the Israelites by the men of Ai.  Or was it simply a statement of a slip in faith?

God reminds them that they will not be able to stand against their enemies unless they destroy the sin within the camp. Notice also that when God reveals the guilty party (Achan), He does it publicly.

Joshua 8 records the battle to attack the city of Ai using an ambush called in today's military terms, "double envelopment".  This same tactic was used in such battles as the Revolutionary War battle of Cowpens.
http://en.wikipedia.org/wiki/Battle_of_Cowpens

Joshua pronounces curses on Jericho. The results of that prophecy happened during Ahab’s reign. Hiel laid the foundations at the cost of his firstborn, the gates at the cost of his youngest son, just exactly what Joshua had predicted as found in 1 Kings 16:34.

IKing 16:34
In Ahab's time, Hiel of Bethel rebuilt Jericho. He laid its foundations at the cost of his firstborn son Abiram, and he set up its gates at the cost of his youngest son Segub, in accordance with the word of the LORD spoken by Joshua son of Nun.

After Ai was taken Joshua copied on stones the law of Moses (the Ten Commandments?), built an altar and read the total Book of the Law, every word to the whole assembly, including women, children, and aliens.

This is great encouragement to read the entire Bible on a regular basis. Just as all of us are doing this year.