By the blast of God, to wit, of his nostrils, as it here follows, i.e. by his anger, which in men shows itself in the nostrils, by hot and frequent breathings there, and therefore by an anthropopathy is ascribed to God; by a secret, and oft undiscerned, but mighty and powerful, judgment of God, by which they are blasted and blown away as chaff by the wind, as the phrase is, Psa 1.
Related Commentaries of Job 4:9
Job 4:9
9 By the blast of God they perish, and by the breatha of his nostrils are they consumed.