Deut 8:9
When you enter the land the Lord your God is giving you, do not learn to imitate the detestable ways of the nations there.

Immediately following this verse, those detestable ways are listed specifically.  Ever wonder if God approves the use of mediums or attempting to consult the dead? Wonder no more! He says those are detestable to Him.  In fact, we are repeatedly warned against this.

There are distinct admonitions listed in Deut 13 concerning signs and wonders done by false prophets. God warns us that these miraculous signs and wonders are done in order to entice us to follow other gods.

Deuteronomy 18:15-19 tells of a true prophet. Many think this passage refers to Jesus. We're not so sure. Could it be that God is simply telling them that there will always be a "go-between" - a prophet who speaks for Him? And that the people should listen?  It is easy to compare this true prophet to John the Baptist.  John was a prophet like Moses (from the line of Levi) and certainly spoke words from God. 

In the laws requiring offerings and sacrifices God gives the Israelites specific instructions. He says time, after time, after time that He wants the firstborn, the first offspring, the best, the firstfruits, etc. God doesn't want the leftovers! What exactly does that mean for us?

Several times we read that the people were to do certain things, "at the place he will choose as a dwelling for his Name."  The place where God put His Name is Israel, specifically Jerusalem, Mt. Zion.  This is the place where Abraham was ready to sacrifice his son Isaac, the threshing floor of David, and where Solomon built the temple, known today as Temple Mount.

There were specific instructions for the triennial.  At the end of every three years, special tithes were given for the aliens, fatherless, and the widows in their towns.  This is a great example of giving to people today as we see the need, not just giving to an established church.

The tithe to the Levites was really a tax from the other tribes. Gifts and offerings were above that.

When God commanded a Sabbath day of rest, He compared our rest to His rest on the seventh day after creation.  There is much speculation as to what day is the Sabbath.  Some say Saturday.  Some say Sunday.  But did God name the days of the week?  Just when did He start counting?  Do we know which day of the week is the seventh day? How can we know?
Rom 14:5-6a 
One indeed esteems a day above another day; and another esteems every day alike. Let each one be fully assured in his own mind. He who regards the day regards it to the Lord; and he not regarding the day, does not regard it to the Lord.

Lev 19:30
Observe (hedge, guard, protect) my Sabbaths and have reverence (respect and honor) for my sanctuary (God's holiness).  I am the Lord.
When God says to hedge, guard and protect His Sabbaths, He wasn't just referring to the weekly Sabbath.  He was also referring to all the Sabbath days, including the commanded Holy Days (Feast of Unleavened Bread, Pentecost, Tabernacles).

Concerning the Sabbath day of rest, the seventh day, did God really need to rest? Was He tired? Hardly!
Isa 40:28
Do you not know? Have you not heard? The LORD is the everlasting God, the Creator of the ends of the earth. He will not grow tired or weary, and his understanding no one can fathom.

At the end of the creating on each "day" we find these words, "and there was evening and morning.." But at the end of the seventh day, those words are significantly absent.  We are still living the seventh day.  What God really did on the seventh day was to look back on all He had accomplished and decided it was good! We are still enjoying the fruits of God's labor.  Is that how He wants us to spend our Sabbath day, looking back on everything that we have done, said, seen, heard, etc. during the previous week?

What can we say about our week? Can we look back and say that it was good?