Rashi on Deuteronomy 32:7/רש"י על דברים ל״ב:ז׳

1זכר ימות עולם REMEMBER THE DAYS OF OLD — what He did to previous generations who provoked Him to anger,

2בינו שנות דר ודר [CONSIDER] THE YEARS OF GENERATION AFTER GENERATION — the generation of Enosh over whom He caused the waters of the ocean to flow, and the generations of the flood whom He drowned by flood (cf. Sifrei Devarim 310:1). Another explanation is: If you have not set your attention to the past (i.e. if you fail to remember the days of old, then) בינו שנות דר ודר CONSIDER at least THE YEARS OF GENERATION AND GENERATION so that you become conscious of what might happen in the future — that He has the power to bestow good upon you and to make you inherit the blissful days of Messiah and the world to come (cf. Sifrei Devarim 310:5).

3שאל אביך ASK THY FATHER — these are the prophets who are termed fathers, as it is stated in the history of Elijah that Elisha exclaimed when Elijah departed, (2 Kings 2:12): “My father, my father, the chariot of Israel!” (cf. Sifrei Devarim 310:3).

4זקניך THY ELDERS — these are the sages,

5ויאמרו לך AND THEY WILL TELL THEE the events of the former days: