Is this the same Daryavesh that the Bayis was built in his second year?
Ibn Ezra: No. That was Daryavesh ha'Parsi; this is Daryavesh ha'Midi. Kadmonim (Megilah 12a) said that [also] Daniel erred. Esther was taken in [Achashverosh's] seventh year (Esther 2:16). She gave birth to Daryavesh in his eighth year 1 . His entire reign was 13 years, so Daryavesh became king when he was six years old. We find that Yeho'ash was seven when he became king, and Yoshiyah was close to this (eight). This Daryavesh was old (62) when he became king. Koresh succeeded him, and then Achashverosh, and Chazal said that Daryavesh ha'Parsi, Esther's son, succeeded him. Even though this Daryavesh is called ben Achashverosh, it is not the Achashverosh who took Esther. He was the father-in-law of Koresh Melech Paras. Koresh made his father-in-law king over Malchus Bavel ? Koresh said "Kol Mamlachos ha'Aretz Nasan Elokim b'Yadi." They ruled at the same time. Therefore, when Kasdim fell, Yisrael ascended from Bavel with Zerubavel, like Koresh commanded. He was the great king.
Esther continued intimacy with Mordechai after Achashverosh took her (Megilah 13b). We require Havchanah (prevention of a Safek about who is the father)! Tosfos (ibid.) says that she used a Moch (wad) to avoid pregnancy from Achashverosh. After she separated from Mordechai in Achashverosh's 12th year (ibid. 15a, Esther 3:7), she did not need a Moch. If Daryavesh was born after this, he was at most two when he became king! Perhaps she did not use a Moch when Achashverosh first took her five years earlier, and became pregnant then. She used a Moch afterwards, and returned to Mordechai after waiting three months. (PF)
Why does the verse teach Daryavesh's age?
Rashi: This teaches that the day that Nebuchadnetzar entered the Heichal in the days of Yechanyah, his 1 nemesis Daryavesh was born. There were 62 years from Galus Yechanyah until now. Galus Yechanyah was seven years after Yehoyakim was conquered, in Nebuchadnetzar's eighth year. Nebuchadnetzar ruled another 37 years, Evil Merodach ruled for 23, and two years of Belshatzar (Megilah 11b) ? this is 62.
Malbim: Because he was old, he could not conduct a great kingdom by himself. Therefore, he appointed others to help him (the coming verse).
I.e. Nebuchadnetzar's nemesis. Daryavesh ended Malchus Bavel.
