Job 4:15 - Ellicott's Commentary On The Whole Bible

A spirit passed before my face. — It is vain to argue from this passage that spiritual essences are capable of being seen by the bodily eye, because, first of all, the language is highly figurative and poetical, and because, secondly, every one understands that a spiritual manifestation can be made only to the spirit. The notion, therefore, of seeing a spirit is absurd in itself, because it involves the idea of seeing the invisible; but it is conceivable that the perceptions of the inner spirit may be so vivid as to assume the character of outward manifestations.