3 - Jesus was faithful in God's house, like Moses, but with greater glory.
So don't let your heart and life wander away from obedience. Maintain your faith to God, so you don't wind up rebellious like Israel in the wilderness. Don't forget the end of Psalm 95.
4 - There is still a rest for God's people to enter. David spoke of it, well after entering Canaan! We receive the rest when we believe (4:3). We have to work at getting this rest (4:11). But Jesus, our sympathetic high priest, will help us.
How this is about Jesus/ Application
3 - This chapter continues the pattern of the book: an assertion that Jesus is greater than some Old Testament thing, then an exhortation to stay faithful to Him in life. In the first two chapters it was angels. Now we turn to Moses and the rest of the promised land.
4 - Our lives are patterned after Israel's OT history. We have to be careful to enter God's rest (faith in Jesus Christ), and not rebel out of laziness or presumption.