General Information:

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

Behold

The word "behold" emphasizes that what is said next is important. "Pay attention" or "Look" or "Listen"

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)