Why does the Navi teach about his children?
Radak citing Bava Basra 91a: This teaches that a person should not become haughty about his wealth or [many] children. Bo'az (Avtzan) did not invite Mano'ach to any of his 60 children's weddings 1 ; he said, 'that sterile mule - when will he [have children and] pay (invite) me in return 2 ?!' He was punished for this, and all 60 of his children died in his lifetime.
Radak #2: He had great success with sons and daughters 3 , and all married in his lifetime. He had this success due to great merits, and due to them he was a Shofet.
Surely this is like the opinion that Mano'ach was Gedol ha'Dor (refer to 13:2:1:1). According to the opinion that he was an ignoramus, why should Bo'az invite him? It is disgraceful for a Chacham to sit with an ignoramus at a meal (Rashi Sanhedrin 23a)! (PF)
Maharsha (91a): The custom was that a guest invited to a wedding would bring gifts of food, and later, when the guest made a wedding, the recipient of the gifts 'returns' (brings) the same amount to him. Bo'az did not invite Mano'ach, lest he receive gifts and have no opportunity to return them. (Even though the reason he did not invite him was due to "v'Sonei Matanos Yichyeh" (Mishlei 15:27), he was punished awesomely. - PF) There is awesome danger in deciding when Midas Chasidus is proper! (Mesilas Yesharim Perek 20)
Bereishis Rabah (37:7) says that Yaktan merited 13 sons because he lowered himself. (And people were still living long lives then. The sum of the years of his father, brother and nephew was 942! (Bereishis 11:16-21) - PF)
