General Information:

Moses continues to speak to the Israelites as if they are one person. (See: rc://en/ta/man/translate/figs-you)

Behold, to

"Pay attention, because what I am about to say is both true and important: to"

These words show two extremes, and are combined to mean that all things everywhere belong to Yahweh. (See: rc://en/ta/man/translate/figs-merism)

This refers to the highest places in the heavens. Everything in the heavens belong to God.

Here the word "you" refers to all the Israelites and is plural. (See: rc://en/ta/man/translate/figs-you)