We have talked about Jer 31:15 as a time marker in Jeremiah’s prophecy in chapter 31. That would be about 4 BC.

In the next part of Jeremiah 31 God talks about Ephraim as a pseudonym for Israel and the Jews, and says,

“Is Ephraim my dear son? is he a darling child? for as often as I speak against him, I do earnestly remember him still: therefore my heart yearns for him; I will surely have mercy on him, says Yahweh.” Jer 31:20 WEB

That is still very much in line with the general subject of Jeremiah 31 as was outlined in Part I. Jeremiah is talking about the Jews, and He also says,

“27 Behold, the days come, says Yahweh, that I will sow the house of Israel and the house of Judah with the seed of man, and with the seed of animal. 28 It shall happen that, like as I have watched over them to pluck up and to break down and to overthrow and to destroy and to afflict, so will I watch over them to build and to plant, says Yahweh.”
Jer 31:27-28 WEB

Again Yahweh is clearly talking about physical Israel, Israel after the flesh, the Jews. Also this once again is clearly in line with Jer 31:1-2 and also verse 20.

Then God talks about the coming of the a New Covenant

Paul quotes Jer 31:31 of the New Covenant in Jesus Christ, and the Jews, as was noted in Part I. Additionally the author of Hebrews quotes Jeremiah 31 in Heb 8:8-12 and again in Heb 10:16-17 of the new covenant as it applies to both Jews and gentiles. It should be noted that God says,

“But this is the covenant that I will make with the house of Israel after those days, says Yahweh: I will put my law in their inward parts, and in their heart will I write it; and I will be their God, and they shall be my people:” Jer 31:33 WEB

Now when did this New Covenant happen? In approximately 30 AD Jesus twas setting up this New Covenant. He was instituting the Lord’s Supper which was to be in commemoration of the shedding of His blood.

“for this is my blood of the new covenant, which is poured out for many for the remission of sins” Mtt 26:28 WEB

Then there was the actual shedding of Jesus blood on the cross at Golgotha, a little later. Then there was Jesus resurrection. Just before Jesus went up to heaven in Acts 1, He told them it was not for them to know the times or seasons, but to wait for the Holy Spirit to come upon them., Acts 1:7-8. The Holy Spirit came in Acts 2 with the first gospel sermon by Peter. In all it is safe to date the New Covenant as coming in 30 AD. So here is another date marker in Jeremiah 31, and it does follow in time “Rachel weeping for her children” in Jer 31:15.

But then comes a problem …

WEB is the World English Bible, a copyright free revision
of the original ASV American Standard Version 1901