Where in the Old Testament does it say that all living things have a soul/spirit?

Answer:

Actually, the soul and spirit are two different things even though they are often used interchangeably.

1 Thessalonians 5:23  And the very God of peace sanctify you wholly; and I pray God your whole spirit and soul and body be preserved blameless unto the coming of our Lord Jesus Christ.

The soul has to do with our thoughts and our emotions, where our spirit is what gives us an understanding of God and of the Heavenly things He has for us.

It does say in the Bible that every living thing has a soul:

Job 12:10  In whose hand is the soul of every living thing, and the breath of all mankind.

Good question,
Pastor Brad