Revelation 5:5
Then one of the elders said to me, “Weep not; lo, the Lion of the tribe of Judah, the Root of David, has conquered, so that he can open the scroll and its seven seals.”
Revelation 5 shows us a picture of a scroll, written on both sides and sealed with seven seals, that no creature can open. This is reminiscent of the Ten Commandments, which represent the entire Old Testament. By this, John the Seer is being shown that the law and the prophets are not fully comprehensible apart from the final revelation of the Messiah.
This is why Jesus had to show disciples (who had been reading the Old Testament all their lives) that he was hidden there and that the whole Old Testament was ultimately pointing to him. He “opened to them the Scriptures” (Luke 24:32) and explained what is was all ultimately pointing to. For the New Testament is hidden in the Old Testament and the Old Testament is only fully understood in light of the New. Today, thank God for the mystery of his gradual self-revelation through his people Israel and the New Israel, which is the Church. The Lion has conquered death and “opened the scroll and its seven seals.”