Radak: Seder Olam says that it was in the days of Kushan Rish'asayim (right after Yehoshua). If we learn from "Kol Yemei? b'Shilo", we must say that Pesel Michah was even in the days of Yehoshua, for in his days they established the Mishkan in Shilo, after 14 years, seven of conquest and seven of division. (Seder Olam 12 says that Yehoshua reigned for 28 years, i.e. including 14 years of Mishkan Shilo.) It is difficult to say so, for "va'Ya'avdu? Es Hashem Kol Yemei Yehoshua" (2:7, Yehoshua 24:31)! Also, it says "Ein Melech b'Yisrael Ish ha'Yashar b'Einav Ya'aseh" (verse 6). This was not in the days of Yehoshua, for even the Mizbe'ach that Bnei Gad and Bnei Reuven, they wanted to go to war, and all the more so [they would have fought against] Pesel Michah! Also refer to 18:1:2:2. A Midrash says that Pesel Michah is written next to Shimshon, in which 1100 silver [pieces] were used for evil (to induce Delilah to discover his secret), and 1100 silver pieces of Michah's mother were used for evil. Pilegesh b'Giv'ah is written after, for the Aveirah of Pesel Michah caused many thousands of Yisraelim to die in the war against Binyamin. If not for Pesel Michah, they would not have died, for it was proper to fight against Binyamin, to eradicate the evil from Yisrael.

Radak: Yerushalayim was conquered in the days of Yehoshua. Melech Yerushalayim is among the kings he struck. "The Yevusi in Yerushalayim, Bnei Yehudah could not dispossess; the Yevusi lived with Bnei Yehudah in Yerushalayim" (Yehoshua 15:63). This shows that they conquered Yerushalayim, except for Metzudas Tziyon, which was not conquered until David. However, not many Yisraelim settled there, due to the Yevusi. The youth suggested that they lodge in the Yevusi city; his master said, "Lo Nasur El Ir Nochri." Malbim (21:25) - the order of the Parshiyos implies that it was after Shimshon died. Also Rashi (Shmuel 1:20:30) explained "Ben Na'avas ha'Mardus" - after Pilegesh b'Giv'ah, Sha'ul was too shy to grab one of the dancing girls; Yehonason's mother chased him. Also, the Yerushalmi (Brachos 9:3) says that Yehonason was a Gizbar in the days of Shlomo, and he was the old prophet in Beis Kel. According to Seder Olam, he lived over 400 years!

If so, Shevet Binyamin multiplied astoundingly! Only 600 men from Binyamin remained after Pilegesh b'Giv'ah. Asa had 280,000 soldiers from Binyamin (about 500 times as many; Divrei ha'Yamim 2:14:7), at most 15 years into his reign (ibid. 2:15:10,11). They were born at least 20 years before this, at most 146 years after Pilegesh b'Giv'ah. On the average, Binyamin doubled about every 16 years - this is close to the rate of Bnei Yisrael multiplying in Egypt! Initially, 600 men owned the land given to 45,600 men, so they could afford to take many wives [and father many children] - however, Bnei Yisrael vowed not to give their daughters to Binyamin, and with difficulty they enabled each of the 600 to get one wife! Perhaps the 280,000 included men from other tribes who had come to live in Binyamin. Many from Malchus Yisrael came to [Yehudah and Binyamin] after they saw Asa's success (ibid. 2:15:9) - but this is written after the 'census' of Binyamin (2:14:7)! (PF)