"your elders, and they shall say it to you": what I showed the elders in the mountain," (Sinai, at the giving of the Torah), viz. (Shemoth 24:1) "And to Moses He said: Go up to the L-rd, you and Aaron, Nadav and Avihu, and seventy from the elders of Israel… (Ibid. 10) And they saw the G-d of Israel" (and so, in time to come.)
(Devarim 32:8):When the Most High caused nations to inherit": Before the advent of our father Abraham, the L-rd judged the world with severity: The men of the flood sinned — He flooded them like sparks on the face of the waters. The men of the tower of Bavel sinned — He scattered them from one end of the world to the other. The men of Sodom sinned — He swept them away with fire and brimstone. But when our father Abraham came to the world, afflictions materialized (in place of destruction), viz. (Bereshith 12:9) "And there was a famine in the land, and Avram went down to Egypt." And if you would ask "Why are there afflictions?" (the answer is) Because of His love for Israel (i.e., to avoid destroying them!)