Jeremiah 6:16 (ESV) … Thus says the Lord: “Stand by the roads, and look, and ask for the ancient paths, where the good way is; and walk in it, and find rest for your souls. But they said, ‘We will not walk in it.’”
God offers rest in repentance and a return to the old paths of trust and obedience. While the people reject His law and His teaching, they continue the hypocrisy of outward religious ceremony and observances.
God will cause His own people to stumble, to show them their need for forgiveness and help from Him, when the cruel invader comes upon them. He then bids them to dress in sackcloth and to mourn in sorrow for their sin.
 Chrispin, G. (2005). The Bible Panorama: Enjoying the Whole Bible with a Chapter-by-Chapter Guide (p. 312). Leominster, UK: Day One Publications.