Numbers 14 - As you read through your Bible you'll come to see some "sad chapters." I've already mentioned a few and here's one more. Israel had the chance to go into the Promised Land at this time but they were discouraged by the bad report given by 10 of the 12 spies who explored Canaan. The people of Israel were even ready to stone Moses and Aaron and return to Egypt! God spoke and Moses intervened to keep God from destroying the people. God made it clear that they would wander in the wilderness for 40 years, one year for each day the spies were in the land of Canaan.
Numbers 15 - God gave reassurance to the people that they would eventually come into the Promised Land. He made sure they understood the seriousness of offering their sacrifices. God made provision for the foreigners living with them to have opportunity to worship Him too. A man gathering sticks on the Sabbath was executed. God required the sewing of blue tassels on their garments to remind them to obey His laws.
Psalm 90 - As you are reading chronologically through the Bible you're being directed to read Psalm 90 which was written by Moses. Its a great passage to speak of God's majesty and man's frailty. God is from everlasting to everlasting but man might live on the earth for 80 years! Quite a contrast. Praise God He has made provision for believers in Christ to spend eternity with Him!