"Reflect upon the years of generation upon generation": There is no generation where there are no men like those of the generations of the men of the flood; where there are no men like those of the generation of hapalagah and the men of Sodom — but each is judged according to his acts.
"Ask your father and he will tell you": These are the prophets, viz. (II Kings 2:12) "And Elisha saw (Eliyahu the prophet) and cried 'My father! My father!'"
"your elders and they will tell you": These are the elders, viz. (Bamidbar 11:16) "Gather unto Me seventy men from the elders of Israel."