At this also - That is, in view of the thunderstorm, for it is that which Elihu is describing. This description was commenced in Job 36:29, and is continued to Job 37:5, and should not have been separated by the division into chapters. Elihu sees a tempest rising. The clouds gather, the lightnings flash, the thunder rolls, and he is awed as with the conscious presence of God. There is nowhere to be found a more graphic and impressive description of a thunder-storm than this; compare Herder on Hebrew Poetry, vol. i., 85ff, by Marsh, Burlington, 1833.
My heart trembleth - With fear. He refers to the palpitation or increased action of the heart produced by alarm.
And is moved out of his place - That is, by violent palpitation. The heart seems to leave its calm resting place, and to burst away because of fright. The increased action of the heart under the effects of fear, as described here by Elihu, has been experienced by all. The “cause” of this increased action is supposed to be this. The immediate effect of fear is on the extremities of the nerves of the system, which are diffused ever the whole body. The first effect is to prevent the circulation of the blood to the extremities, and to drive it back to the heart, and thus to produce paleness. The blood thus driven back on the heart produces an increased action there to propel it through the lungs and the arteries, thus causing at the same time the increased effort of the heart, and the rapid action of the lungs, and of course the quick breathing and the palpitation observed in fear. See Scheutzer, Physica. Sacra, in loc. An expression similar to that which occurs here, is used by Shakespeare, in Macbeth:
“Why do I yield to that suggestion,
Whose horrid image doth unfix my hair,
And make ray seated heart knock at my ribs
Against the use of nature.”