When Elihu saw that [there was] no answer in the mouth of
[these] three men
That could be called an answer; nay, when he perceived they were quite nonplussed and silenced, though men of years and experience, and reputed wise and knowing:
then his wrath was kindled;
his spirit was stirred up; his heart was hot within him; he burned with anger against those men; he was all on fire, as it were, and wanted to vent his resentment.