Why did Hashem send specifically a famine?
Radak citing Eruvin 63a: The previous verse teaches that David used to give all of his Matanos Kehunah to one Kohen (Ira). This causes a famine!
Malbim: Because Sha'ul and Yisrael caused hunger to the Giv'onim, so occurred to them.
Why did David not seek Hashem before the third year?
Radak citing Rav Sadya Gaon: The first year he thought that it is chance, like happens in the world. The second year he thought that it is due to the sin of Pesel Michah; he eradicated everything that he found of it 1 . When the famine continued the next year, he knew that there is a different cause.
Malbim citing Yevamos 78b: The first year David suspected that it is due to idolatry amidst Yisrael - "And you will serve foreign gods ... and there will not be rain" (Devarim 11:16). He checked and did not find idolatry. The second year he suspected that it is due to immorality - "The early and late rains were withheld, and you had the countenance of a harlot" (Yirmeyah 3:3). He checked, and did not find. In the third year he did not find the sin 2 , so he asked the Urim v'Tumim.
Rashi (Shoftim 18:30, from Yerushalmi Brachos 9:3): "Yehonason and his sons were Kohanim [of Pesel Michah]
What is the meaning of "El Sha'ul v'El Beis ha'Damim"?
Rashi: "Sha'ul" is the sin regarding Sha'ul. He was buried suddenly and covertly; Anshei Yavesh Gil'ad stole his body from the Pelishtim, and he was not eulogized properly. Beis ha'Damim is that he killed Nov, Ir ha'Kohanim.
Radak: El Beis ha'Damim refer to the seven survivors from those (i.e. Beis Sha'ul) who killed the Giv'onim; the Giv'onim demanded to kill them (verse 6). Refer to 21:7:2:3.
Malbim: Sha'ul killed some of the Giv'onim, and Beis ha'Damim (his household and helpers) expelled them from joining in Nachalas Hashem, so many died from hunger and poverty. It includes Beis Yisrael, who were still drawn after Sha'ul's decree; the sin is primarily attributed to Sha'ul, who caused them to be despoiled. Hashem was angry at this generation for not fixing the matter.
Did Sha'ul kill Giv'onim?
Rashi citing Yerushalmi Sanhedrin 6:7: He killed seven when he killed Nov - two wood choppers, two water carriers, a scribe, and an overseer and Gabai [of the Beis ha'Keneses].
Rashi citing Yevamos 78b: He killed the Kohanim of Nov, who used to supply food and water to the Giv'onim, the verse considers it as if he killed them.
Radak: This does not refer to the Giv'onim killed among the Kohanim. "Ha'Ish Asher Kilanu va'Asher Dimah Lanu" (verse 5) implies that he harmed them alone. Also, it says "b'Kin'aso li'Vnei Yisrael vi'Yhudah"! Rather, he decreed that they not chop wood and draw water for Beis Hashem. It is better than Yisrael serve in front of Hashem. Also, the Giv'onim deceived Yisrael; the Nesi'im mistakenly swore to them (they claimed not to be from the seven Kena'ani nations). Sha'ul had Kin'ah for this, and killed some and expelled the rest, that they not dwell in Eretz Yisrael - "Nishmadnu me'Hisyatzev b'Chol Gevul Yisrael" (verse 5). 1
Maharsha (Yevamos 78b): The Giv'onim used to supply food and water to the Kohanim. Sha'ul deprived them of this great merit. 2
Malbim: After Sha'ul killed the Giv'onim in Nov, he poured his wrath against Giv'onim in other cities and commanded to eradicate them or expel them from the land - "va'Yvakesh Sha'ul Lehakosam" (verse 2) , for he thought that they were with the Kohanim who rebelled. Even though Yehoshua swore 3 not to kill them, they transgressed the Bris by rebelling against the king. Even though Sha'ul did not eradicate or expel them, they became 'Hefker'; people expelled them and did to them as they wanted.- "Nishmadnu me'Hisyatzev b'Chol Gevul Yisrael" (verse 5). Even when the Kohanim were returned to their honor (after Sha'ul died), there was no correction of the injustice done to the Giv'onim, for they were disgraced in people's eyes. Chazal say that this was towards the beginning of David's reign, before Avshalom's rebellion. 4
Radak: Even though Sha'ul had good intent, he was punished, for Yehoshua Navi Hashem made them wood choppers and water drawers for Beis Hashem, and did not want to kill them due to the Nesi'im's Shevu'ah, even though it was mistaken, due to Chilul Hashem. People will say, they swore to keep them alive, and then killed them - Shevu'as Hashem is not important in their eyes! All the more so in the days of Sha'ul, many generations later, they had settled in Yisrael, it was a great Chilul Hashem to kill them. Sha'ul was not concerned for the Chilul Hashem due to the Shevu'ah, therefore his seed was punished.
After Nov was destroyed, the Mishkan moved to Giv'on. The Giv'onim could have supplied the Kohanim there with food and water! Perhaps it was too hard for them to relocate, or the Kohanim in Giv'on already had a source of food and water. Bamidbar Rabah 8:4 ('he cut off our food') implies like Rashi (refer to 21:1:5:2). (PF)
Yehoshua 9:15: Yehoshua made a Bris with them, and Nesi'ei ha'Edah swore to them. Perhaps Yehoshua in included in Nesi'ei ha'Edah, or the Shevu'ah is called on his name. (PF)
According to Shabbos 56b, that when David gave Mefiv`oshes' field to Tziva, Mefivoshes said ' My complaints are
QUESTIONS ON RASHI
Rashi writes that one reason was the killing of Nov, Ir ha'Kohanim. Was there not already punishment for this?
Malbim citing Mahari, based on Rav Sadya Gaon: Sha'ul received three punishments. (a) For not waiting for Shmuel in Gilgal, his kingship did not pass to his descendants. (b) For having mercy on Agag 1 , kingship was torn from him and his life was shortened. (c) For killing the Kohanim in Nov, he and his sons died by the sword and were not buried and eulogized properly. Since Yisrael did not protest against him [killing the Kohanim], many of them died with him. He was not punished for killing the Giv'onim in his lifetime, for it was not so severe. The punishment came after his death, on his minor children and his Pilegesh's children. The punishments [of Sha'ul and Yisrael] came together, so now they were punished with famine for not protesting. Hashem has deep reasons why He delayed the punishment so many years. Bi'Ydei Shamayim, children are punished for their parents' sin if they persist in it.
And the animals (PF).
Rashi writes that Hashem punished for not properly eulogizing Sha'ul, and also for Sha'ul's sin. Is this reasonable?!
Rashi citing Yevamos 78b: Yes! "Ba'Asher Mishpato Pa'alo" (Tzefanyah 2:3) - when Hashem judges a person, He recounts his righteous acts.