In Jeremiah 23:5,6 we see Jeremiah prophesying about the coming of the Lord Jesus Christ who is called, here, 'the Righteous Branch' and 'The Lord our righteousness.'
This title refers to the Lord as the One Who justifies us by imputing His righteousness to us. It is a new-covenant title - and Jeremiah prophesied quite a bit about the new covenant.
This chapter is also a wonderful chapter for all preachers to read, because there are many warnings given here for them to take heed of. False prophets are exposed and denounced here. They were false prophets because they did not take time to listen to what God was saying (Jeremiah 23:18). They were too lazy to stand before God and wait for His Word.
There are many false prophets moving around in Christendom today, who seek honour and money for themselves. They prophesy falsely about imaginary dreams they claim to have dreamt.
Jeremiah warned the people not to listen to false prophets. They invented their own messages and spoke to the people, saying "Thus says the Lord". But the Lord had not spoken to them. There are numerous people carelessly using that phrase even today. It is very dangerous to get up and say, "Thus says the Lord", when you are not sure whether God has really spoken. People who have no fear of God whatsoever use that phrase today and say whatever comes into their mind. This is dangerous and evil.
All such people should read this chapter and learn to fear God. God does speak, but he speaks through humble people like Paul who said, "I think I have the Spirit of God" (1 Cor. 7:40) - and not through people who arrogantly say, "Thus says the Lord". Beware of such false prophets - for there are thousands of them in Christendom today.
God says that His word is like fire and a hammer (Jeremiah 23:29). Why are the words of so many preachers unable to break the hard hearts of people and set them on fire? It is because their words did not come from the Lord.