The Greek text specifically says "the spirit and the soul and the body" distinguishing between the three.
The Hebrew text doesn't distinguish between spirit and soul as clearly as the Greek; that is why many scholars interpret the spirit and the soul as one.
But it's inconsistent with Hebrews 4:12, which clearly states that the "quick and powerful" Word of God can divide the soul and spirit.
Since they can be divided [even though only by the Word of God], spirit and soul must have distinguishable characteristics.