It's a poem (not a proverb).
Everyone has wishes. The heavens will grant us our wishes.
I wish we were beasts in far-off lands. Every step we took we would take together.
I wish we were trees deep in the mountains. Every branch of ours would be intertwined.
This is someone proposing to be very close friends or lovers!
If you use a western method of literary analysis, the imagery is sexual: beasts, intertwined.