Prophets don't see everything

God , through Jeremiah, proclaimed a new covenant to replace the old.
Behold, the days are coming, says the LORD, when I will make a new covenant with the house of Israel and the house of Judah (Jeremiah 31:31).
While Moses inscribed the 10 Commandments on two tablets of stone, God would inscribe the law in the hearts of men.
But this is the covenant which I will make with the house of Israel after those days, says the LORD: I will put my law within them, and I will write it upon their hearts; and I will be their God, and they shall be my people (Jeremiah 31:33).
In the new covenant, men follow the law, which is no longer imposed from without, but from within their hearts. When the law is imposed from without, men need teachers of the law to teach them. They follow the law out of fear of punishment. When the law is inscribed in their hearts, men know the law. No longer can they claim ignorance and disclaim their obligations. Men are no longer animals but moral beings. Following the law becomes sweet and satisfying. It is an evolution.
In Jeremiah 17, we find what was inside men's hearts.
The sin of Judah is written with a pen of iron; with a point of diamond it is engraved on the tablet of their heart, and on the horns of their altars (Jeremiah 17:1).
Now, the evil thoughts inside their hearts are replaced by the law of God. In this new covenant, a breath of fresh air infiltrates the whole being. The Holy Spirit infuses the whole person. God will forgive their iniquity and remember their sins no more (Jeremiah 31:34).
Alas! All sorts of negative feelings and desires continuously spring out from men's hearts. But men have an arsenal of defence mechanisms to repress them. To make life tolerable and comfortable, men deny, suppress and project their guilt. Beginning with Adam, men have developed a bad habit of playing the not-me game. Men began to alienate themselves and soon could not even recognize their true selves. They needed someone from without to tell them the truth.
I the LORD search the mind and try the heart, to give to every man according to his ways, according to the fruit of his doings (Jeremiah 17:10).
In the days of old, God checked and balanced our indulgence. When the law is written in our hearts, we develop self-discipline. After years of a disciplined life, we may follow the desires of our hearts without breaching the law.
七十而從心所欲，不踰矩。【論語‧為政】God does not need to search our mind and try our hearts any more!
Jesus clashed with the Jewish leaders, especially over the issue of keeping the Sabbath. The gospels give us Jesus' side of the story. Reading Jeremiah, we may become more sympathetic towards the Pharisees. The Torah is very strict in forbidding people to work on Sabbath. People breaking this law were put to death (Exodus 31:14-15). Jeremiah did not threaten people with death. God told him to go and stand in the Benjamin Gate to exhort people to keep Sabbath holy and do no work on it (Jeremiah 17:24). No wonder the Pharisees were so hostile to Jesus. They would not appreciate, nor accept Jesus' humanitarian principle: the Sabbath was made for man, not man for Sabbath (Mark 2:27).
Progressive though Jeremiah was, he had not seen everything. He was only given visions of kings riding in chariots and horses to enter Jerusalem through the Benjamin Gate (Jeremiah 17:25). We have to wait until a Zechariah to see the Messiah entering Jerusalem on an ass (Zechariah 9:9). Prophets don't see everything.

My Lord, clear up the defence mechanisms in my psyche. May the Law You have written in my heart be my guide to lead me home. Open my ears to hear the sweet whispers of Yours. Amen.