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."

My heart trembleth - This is what the Septuagint has anticipated; see under Job 36:28 (note). A proper consideration of God's majesty in the thunder and lightning is enough to appall the stoutest heart, confound the wisest mind, and fill all with humility and devotion. This, to the middle of Job 37:5, should be added to the preceding chapter, as it is a continuation of the account of the thunder and lightning given at the conclusion of that chapter. Our present division is as absurd as it is unfortunate.

At this also my heart (a) trembleth, and is moved out of his place.
(a) At the marvelling of the thunder and lightnings: by which he declares that the faithful are lively touched with the majesty of God, when they behold his works.

At this also my heart trembleth,.... At the greatness and majesty of God, not only as displayed in those works of his before observed, but as displayed in those he was about to speak of: such terrible majesty is there with God, that all rational creatures tremble at it; the nations of the world, the kings and great men of the earth, and even the devils themselves, Isaiah 64:2. Good men tremble in the worship of God, and at the word of God; and even at the judgments of God on wicked men, and at the things that are coming on the churches of Christ. But Elihu has a particular respect to thunder and lightning, which are very terrible to many persons (s), both good and bad (t). At the giving of the law, there were such blazes of lightning and claps of thunder, that not only all the people of Israel in the camp trembled, but Moses himself also exceedingly feared and quaked, Exodus 19:16. It is very probable, that at this time Elihu saw a storm gathering, and a tempest rising; some flashes of lightning were seen, and some murmurs (u) of thunders heard, which began to affect him; since quickly after we read that God spoke out of the whirlwind or tempest, Job 38:1;
and is moved out of his place; was ready to leap out of his body. Such an effect had this phenomenon of nature on him; as is sometimes the case with men at a sudden fright or unusual sound, and particularly thunder (w).
(s) , &c. Homer. Il. 10. v. 94, 95. (t) As it was to Augustus Caesar, who always carried about with him the skin of a sea calf, as a preservative; and, on suspicion of a storm rising, would betake himself to some secret and covered place: and to Tiberius, who wore his laurel to secure him from it: and to Caligula, who, on hearing it, would get out of bed and hide himself under it. Sueton. Vit. August. c. 90. Tiber. c. 69. & Caligul. c. 51. Plin. Nat. Hist. l. 15. c. 30. Vid. Virgil. Georgic. l. 1. v. 330, 331. (u) "Tonitruorum unum genus grave murmur----aliud genus est acre quod crepitum magis dixerint". Senecae Quaest. Nat. c. 2. c. 27. (w) "Attonitos, quorum mentes sonus ille coelestis loco pepulit". Ibid.

The changes of the weather are the subject of a great deal of our thoughts and common talk; but how seldom do we think and speak of these things, as Elihu, with a regard to God, the director of them! We must notice the glory of God, not only in the thunder and lightning, but in the more common and less awful changes of the weather; as the snow and rain. Nature directs all creatures to shelter themselves from a storm; and shall man only be unprovided with a refuge? Oh that men would listen to the voice of God, who in many ways warns them to flee from the wrath to come; and invites them to accept his salvation, and to be happy. The ill opinion which men entertain of the Divine direction, peculiarly appears in their murmurs about the weather, though the whole result of the year proves the folly of their complaints. Believers should avoid this; no days are bad as God makes them, though we make many bad by our sins.

(Job 37:1-24)
At this--when I hear the thundering of the Divine Majesty. Perhaps the storm already had begun, out of which God was to address Job (Job 38:1).

1 Yea, at this my heart trembleth
And tottereth from its place.
2 Hear, O hear the roar of His voice,
And the murmur that goeth out of His mouth.
3 He sendeth it forth under the whole heaven,
And His lightning unto the ends of the earth.
4 After it roareth the voice of the thunder,
He thundereth with the voice of His majesty,
And spareth not the lightnings, when His voice is heard.
5 God thundereth with His voice marvellously,
Doing great things, incomprehensible to us.
Louis Bridel is perhaps right when he inserts after Job 36 the observation: L'clair brille, la tonnerre gronde. לזאת does not refer to the phenomenon of the storm which is represented in the mind, but to that which is now to be perceived by the senses. The combination שׁמעוּ שׁמוע can signify both hear constantly, Isaiah 6:9, and hear attentively, Job 13:17; here it is the latter. רגז of thunder corresponds to the verbs Arab. rḥz and rjs, which can be similarly used. The repetition of קול fo noititeper eh five times calls to mind the seven קולות (ἑπτὰ βρονταί) in Psalm 29:1-11. The parallel is הגה, Job 37:2, a murmuring, as elsewhere of the roar of the lion and the cooing of the dove. The suff. of ישׁרהוּ refers to the thunder which rolls through the immeasurable breadth under heaven; it is not perf. Piel of ישׁר (Schlottm.), for "to give definite direction" (2-Chronicles 32:30) is not appropriate to thunder, but fut. Kal of שׁרה, to free, to unbind (Ew., Hirz. and most others). What Job 37:3 says of thunder, Job 37:3 says of light, i.e., the lightning: God sends it forth to the edges, πτέρυγες, i.e., ends, of the earth. אחריו, Job 37:4, naturally refers to the lightning, which is followed by the roar of the thunder; and יעקּבם to the flashes, which, when once its rumble is heard, God does not restrain (עקּב = עכּב of the Targ., and Arab. ‛aqqaba, to leave behind, postpone), but causes to flash forth in quick succession. Ewald's translation: should He not find (prop. non investigaverit) them (the men that are to be punished), gives a thought that has no support in this connection. In Job 37:5 נפלאות, mirabilia, is equivalent to mirabiliter, as Daniel 8:24, comp. Psalm 65:6; Psalm 139:14. ולא נדע is intended to say that God's mighty acts, with respect to the connection between cause and effect and the employment of means, transcend our comprehension.