Lk 24:25-27,32,44-47, Acts 8:34-35, Acts 17:2-3
In the Old Testament, when Ezra the priest gathered all the people of Israel and taught them to understand the book of the Law of Moses, the people wept when they heard the word of the Law. (Neh 8:1-9)
Neh 8:1 And all the people gathered themselves together as one man into the street that was before the water gate; and they spake unto Ezra the scribe to bring the book of the law of Moses, which the Lord had commanded to Israel. 2 And Ezra the priest brought the law before the congregation both of men and women, and all that could hear with understanding, upon the first day of the seventh month. 3 And he read therein before the street that was before the water gate from the morning until midday, before the men and the women, and those that could understand; and the ears of all the people were attentive unto the book of the law. 4 And Ezra the scribe stood upon a pulpit of wood, which they had made for the purpose; and beside him stood Mattithiah, and Shema, and Anaiah, and Urijah, and Hilkiah, and Maaseiah, on his right hand; and on his left hand, Pedaiah, and Mishael, and Malchiah, and Hashum, and Hashbadana, Zechariah, and Meshullam. 5 And Ezra opened the book in the sight of all the people; (for he was above all the people;) and when he opened it, all the people stood up: 6 And Ezra blessed the Lord, the great God. And all the people answered, Amen, Amen, with lifting up their hands: and they bowed their heads, and worshipped the Lord with their faces to the ground. 7 Also Jeshua, and Bani, and Sherebiah, Jamin, Akkub, Shabbethai, Hodijah, Maaseiah, Kelita, Azariah, Jozabad, Hanan, Pelaiah, and the Levites, caused the people to understand the law: and the people stood in their place. 8 So they read in the book in the law of God distinctly, and gave the sense, and caused them to understand the reading. 9 And Nehemiah, which is the Tirshatha, and Ezra the priest the scribe, and the Levites that taught the people, said unto all the people, This day is holy unto the Lord your God; mourn not, nor weep. For all the people wept, when they heard the words of the law.
The resurrected Jesus appeared to his disciples and explained the Old Testament so that they could realize that he was the Christ. (Luke 24:25-27, 32,45-47)
Luke 24:25 Then he said unto them, O fools, and slow of heart to believe all that the prophets have spoken: 26 Ought not Christ to have suffered these things, and to enter into his glory? 27 And beginning at Moses and all the prophets, he expounded unto them in all the scriptures the things concerning himself. 32 And they said one to another, Did not our heart burn within us, while he talked with us by the way, and while he opened to us the scriptures? 45 Then opened he their understanding, that they might understand the scriptures, 46 And said unto them, Thus it is written, and thus it behooved Christ to suffer, and to rise from the dead the third day: 47 And that repentance and remission of sins should be preached in his name among all nations, beginning at Jerusalem.
Philip explained the Old Testament to the Ethiopian eunuch so that he realized that Jesus was the Christ. (Acts 8:34-35)
Acts 8:34 And the eunuch answered Philip, and said, I pray thee, of whom speaketh the prophet this? of himself, or of some other man? 35 Then Philip opened his mouth, and began at the same scripture, and preached unto him Jesus.
At the three Sabbaths, Paul explained the Old Testament and testified that Jesus was the Christ. (Acts 17:2-3)
Acts 17:2 And Paul, as his manner was, went in unto them, and three sabbath days reasoned with them out of the scriptures, 3 Opening and alleging, that Christ must needs have suffered, and risen again from the dead; and that this Jesus, whom I preach unto you, is Christ.