Albert Barnes Commentary Psalms 50:11

"I know all the birds of the mountains; And the wild beasts of the field are mine." — Psalms 50:11 (ASV)

I know all the fowls of the mountains - That is, I am fully acquainted with their numbers, their nature, their habits, and their residence. I have such a knowledge of them that I could appropriate them to my own use if I were in need of them. I am not, therefore, dependent on people to offer them, for I can use them as I please.

And the wild beasts of the field are mine - Margin, “with me.” That is, they are before me. They are never out of my presence. At any time, therefore, I could use them as I might need them. The word rendered “wild beasts” - זיז zı̂yz - means any moving thing; and the idea here is, whatever moves in the field, or roams abroad. Everything is his - whether on the mountains, in the forest, or in the cultivated field.