Zech 12:10, Acts 2:36-37, Acts 16:29-31
In the Old Testament, King Josiah found the book of the law in the temple, read it, and repented. King Josiah knew that the people of Israel had not done what was written in the book of the law and that they had received the wrath of God. (2 Chronicles 34:19-21)
2 Chronicles 34:19 And it came to pass, when the king had heard the words of the law, that he rent his clothes. 20 And the king commanded Hilkiah, and Ahikam the son of Shaphan, and Abdon the son of Micah, and Shaphan the scribe, and Asaiah a servant of the king's, saying, 21 Go, enquire of the Lord for me, and for them that are left in Israel and in Judah, concerning the words of the book that is found: for great is the wrath of the Lord that is poured out upon us, because our fathers have not kept the word of the Lord, to do after all that is written in this book.
It was foretold in the Old Testament that the Israelites would mourn over the Christ whom they had pierced. (Zec 12:10)
Zec 12:10 And I will pour upon the house of David, and upon the inhabitants of Jerusalem, the spirit of grace and of supplications: and they shall look upon me whom they have pierced, and they shall mourn for him, as one mourneth for his only son, and shall be in bitterness for him, as one that is in bitterness for his firstborn.
When the Israelites learned that Jesus, whom they had crucified, was the Christ, the Israelites repented. (Acts 2:36-37)
Acts 2:36 Therefore let all the house of Israel know assuredly, that God hath made the same Jesus, whom ye have crucified, both Lord and Christ. 37 Now when they heard this, they were pricked in their heart, and said unto Peter and to the rest of the apostles, Men and brethren, what shall we do?