The next verse explains the character of the New Covenant; once Jehovah wrote His law on tables of stone, but now:--
"This is the covenant which I will conclude with the House of Israel after those days--it is the utterance of Jehovah-- I will put My law within them, and will write it upon their heart; And I will be their God, and they shall be My people."
These last words were an ancient formula for the immemorial relation of Jehovah and Israel, but they were to receive new fulness of meaning. The inner law, written on the heart, is in contrast to Mosaic ordinances. It has, therefore, two essential characteristics: first, it governs life, not by fixed external regulations, but by the continual control of heart and conscience by the Divine Spirit; secondly, obedience is rendered to the Divine Will, not from external compulsion, but because man's inmost nature is possessed by entire loyalty to God. The new law involves no alteration of the standards of morality or of theological doctrine, but it lays stress on the spiritual character of man's relation to God, and therefore on the fact that God is a spiritual and moral being. When man's obedience is claimed on the ground of God's irresistible power, and appeal is made to material rewards and punishments, God's personality is obscured and the way is opened for the deification of political or material Force. This doctrine of setting aside of ancient codes by the authority of the Inner Law is implied in many passages of our book. The superseding of the Mosaic Law is set forth by a most expressive symbol,[434] "When ye are multiplied and increased in the land, 'The Ark of the Covenant of Jehovah' shall no longer be the watchword of Israel: men shall neither think of the ark nor remember it; they shall neither miss the ark nor make another in its place." The Ark and the Mosaic Torah were inseparably connected; if the Ark was to perish and be forgotten, the Law must also be annulled.
Jeremiah moreover discerned with Paul that there was a law in the members warring against the Law of Jehovah: "The sin of Judah is written with a pen of iron, and with the point of a diamond: it is graven upon the table of their heart, and upon the horns of their altars."[435]
Hence the heart of the people had to be changed before they could enter into the blessings of the Restoration: "I will give them an heart to know Me, that I am Jehovah: and they shall be My people, and I will be their God: for they shall return unto Me with their whole heart."[436] In the exposition of the symbolic purchase of Hanameel's field, Jehovah promises to make an everlasting covenant with His people, that He will always do them good and never forsake them. Such continual blessings imply that Israel will always be faithful. Jehovah no longer seeks to ensure their fidelity by an external law, with its alternate threats and promises: He will rather control the inner life by His grace. "I will give them one heart and one way, that they may fear Me for ever; ... I will put My fear in their hearts, that they may not depart from Me."[437]
We must not, of course, suppose that these principles--of obedience from loyal enthusiasm, and of the guidance of heart and conscience by the Spirit of Jehovah--were new to the religion of Israel. They are implied in the idea of prophetic inspiration. When Saul went home to Gibeah, "there went with him a band of men, whose hearts God had touched."[438] In Deuteronomy, Israel is commanded to "love Jehovah thy God with all thine heart, and with all thy soul, and with all thy might. And these words, which I command thee this day, shall be in thine heart."[439]