'Son' in the Bible

The words of the Teacher, the son of David, king in Jerusalem.

Consider someone who is alone, having neither son nor brother. There is no end to all of his work, and he is never satisfied with wealth. "So for whom do I work," he asks, "and deprive myself of pleasure?" This, too, is pointless and a terrible tragedy.

and that wealth is lost in troubled circumstances. Then a son is born, but there is nothing left for him.

So learn from them, my son. There is no end to the crafting of many books, and too much study wearies the body.