There is a basic about Bible reading and comprehension that many who have not been well formed in their faith do not realize. When one reads the Bible, there are many little footnotes per page, in the tiniest reading (I need glasses AND my magnifying glass to read them myself!) Many Bible readers ignore them, and for quick looking up of a passage and enjoyment that is fine.
Others assume that the footnotes are the way modern books indicate "if you want more information, go here." And so people mostly assume they don't need more information and think that that is that.
Still others glance at the footnotes and in the Gospel, seeing they reference other Gospels, assume that the footnotes just point you to the same events that you are reading about, referenced in one of the other three Gospels, or cited by the Apostles in the Epistles. Or they assume, and this is also often true, that the footnotes are provided by the Bible scholars to point back in the Old Testament to prophesies that pertain to Jesus so you can see the event as being one of those prophesied by the prophets.
But here is an extraordinary thing that everyone once knew, and many have forgotten, which is that the footnotes help you read exactly the scripture that Jesus himself quotes from! Jesus preached daily in the Temple (when in Jerusalem) or in the local synagogues. So Jesus did much more preaching than is recorded, obviously, in the Gospel. Nothing important is left out, but I am teaching you that Jesus did what many do today, which is to preach and to abundantly "quote scripture!"
Here is one of the most famous of the sayings of Jesus, evidence of what I am saying that he preached daily, and further, I want to help you understand the solid scriptural foundation of what Jesus said, and how he constantly referenced to the Old Testament prophets and the teachings of God.
Luke 19: 45-48
And he entered the temple, and began to cast out those who were selling and buying in it, saying to them, "It is written, My house is a house of prayer, but you have made it a den of thieves."
And he was teaching daily in the temple.
But the chief priests and the Scribes and the leading men of the people sought to destroy him; but they found nothing that they could do to him, for all the people hung on his words.
Just about everyone knows about Jesus kicking the moneychangers out of the temple. And many know that he made "a quote." But if you do not look up the footnote, you will miss seeing the actual scripture that Jesus is quoting, and its full glory! Jesus is not just repeating some saying. Jesus quotes either God or one of the prophets directly from holy scripture. So when he quoted, trust me, the faithful recognized what he was saying and recognized directly the source. So when Jesus quoted My house is a house of prayer read from where he is quoting:
Isaiah 56: 1, 7
Thus says the Lord...
them I will bring to my holy mountain and make joyful in my house of prayer; their holocausts and sacrifices will be acceptable on my altar, for my house shall be called a house of prayer for all peoples.
Jesus is quoting God in the scriptures.
But hold your hats, wait until you see the second section of scripture that Jesus is citing. Follow the footnote in your Bible to Jer 7:11.
Jeremiah 7: 1, 11
The following message came to Jeremiah from the Lord...
Has this house which bears my name become in your eyes a den of thieves?
See, if you follow the footnotes and read the Old Testament that Jesus is citing, you not only know more clearly what he is saying, and you see his authority as he not only teaches but preached with more knowledge to even the wise, but most importantly you hear and comprehend Jesus exactly as a pious and devout listener would have heard him. He was not just giving some rabble rousing political or spiritual speeches, as those who try to detract today in modern times from Jesus like to allege. When you read the actual parts of the scripture that Jesus is citing in its fullness, you recognize that the listeners of his day knew right away what passages he was citing and the authority from God that he was invoking. That rocked the world.
See, many Jesus detractors today think people came "just for the miracles," assuming of course that the miracles "actually happened." And yes, many, many people brought their sick to be cured. But they stayed and listened, and THIS is the type of thing that they heard. It is what Jesus said, not what miracles he performed, that changed the world. You see, the ability to perform miracles came from God, and so he performed miracles out of love for their suffering, but also to show in a way that everyone could understand the authority he had received from God. Because, obviously, only God could provide the ability to perform the type of miracles that Jesus performed for the benefit of thousands of people.
But Jesus equally powerfully asserted his authority through words, by quoting God and the prophets and then fulfilling those words. THAT "wowed" the people and demonstrated his authority just as much as the miracles.
Go back to the first reading. Notice something? Jesus is not performing miracles in the temple at all. He is preaching, and he is packing them in. "And he was teaching daily in the temple... for all the people hung upon his words."
Do you see more clearly why the chief priests and the Scribes hated and feared him so? He was able to fulfill admonishments from the Lord God himself to keep the temple a house of prayer, and not a den of thieves, and then literally move in there and preach the authoritative word of God day after day, packing the people in (who prevented his enemies from making a move to harm him) and all without the use of miracles.
Ha, ha, now you can really savor what happens next. I won't type it in here, but if you read the beginning of Chapter 20, you will see just what I am saying happens. Jesus goes on preaching day after day, until finally the chief priests and Scribes regrouped and challenged him. And what do they say? "Tell us, by what authority dost thou do these things? Or who is it that gave thee this authority?"
See, they recognized all that Jesus preached and knew full well whose authority he was citing, as all the priests and Scribes would know by heart what Jesus cites. So that is why they use the word "authority" in their challenge to him, because they knew absolutely very well whose authority Jesus invokes. They try to trap him into saying so, but Jesus eludes them with a counter-question, which they cannot answer.
I hope you find this helpful, on several levels. It deepens your faith to understand what exactly Jesus is saying, and how he established his authority through not just miracles, but by sound and firm scriptural references that resonated with all the people who thronged to listen to him. He took over the temple, essentially, preaching to the crowds but not in a "praise and worship" kind of way that many modern Christians think of when they hear "preaching." Jesus preached the word of God as already revealed in the scripture, and pointed out the failure of the chief priests and Scribes to remain true to what God has commanded. So you can better understand Jesus and all the events, plus deepen your faith by seeing the continuity between what was said and prophesied in the Old Testament and how Jesus cited and fulfilled it day by day, not just at his death and resurrection. Also, you can "take your place in the crowd," by hearing the words Jesus said just as how he would have meant them and how the faithful would have recognized what he cited of God's word and how people can implement and be faithful to what God truly wants from them. This is how Jesus performed his ministry.