Мидраш к Ирмеяу 3:2

4) R. Yehudah says: It is written (Jeremiah 3:23) "And you have polluted the land with your harlotries and with your wickedness. Therefore, the showers have been withheld, and there has been no latter rain; and you had a harlot's forehead; you refused to be ashamed."

... “And David went and he took the bones of Saul and the bones of Jonathan his son from the men of Jabesh- gilead… And he brought up from there the bones of Saul and the bones of Jonathan his son…” (Shmuel II 21:12-13) What did David do? He went and gathered all the elders and great ones of Israel, crossed the Jordan River, and came to Yavesh-gilead. He found the bones of Shaul and his son Yonatan, placed them in a casket and crossed back over the Jordan, as it says “And they buried the bones of Saul and Jonathan his son in the country of Benjamin in Zela, in the tomb of Kish his father and they did all that the king commanded…” (Shmuel II 21:14) What does ‘in Zela, in the tomb of Kish his father’ mean? It comes to teach us that they brought them to the border of Jerusalem and buried them there. Zela is next to Jerusalem, as it says “And Zelah, Eleph, and the Jebusite, which is Jerusalem…” (Yehoshua 18:28) ‘and they did all that the king commanded’ And what did the king command? He commanded that they carry Shaul’s casket from tribe to tribe. As Shaul’s casket entered each tribe’s territory all the men, women and children came out in order to perform an act of loving kindness to Shaul and his sons and thereby all of Israel would fulfill its obligation to loving kindness. This went on until they reached the land of his portion on the border of Jerusalem. Since the Holy One saw that they did loving kindness to Shaul and fulfilled the judgement of the Givonites He was immediately filled with mercy and sent rain upon the land, as it says “And God was entreated for the land after that.” (Shmuel II 21:14) From this we learn how close the Holy One brings those that are far away, even though they converted not for the sake of heaven. There is no need to even mention how he draws near righteous converts, “O Lord, all the kings of the earth will acknowledge You…” (Tehillim 138:4)

In the second year all Israel went up (to celebrate) the festivals. David said to them: Go forth and see if there be among you people who lead immoral lives, because owing to the sin of immorality the heavens are closed, as it is said, "And thou hast polluted the land with thy whoredoms" (Jer. 3:2). What is written after this in this context? "Therefore the showers have been withholden, and there hath been no latter rain" (Jer. 3:3). They investigated, but they did not find (any immoral people).