Behold, God is great, and we know him not - That is, we cannot fully comprehend him; see the notes at Job 11:7-9.
Neither can the number of his years be searched out - That is, he is eternal. The object of what is said here is to impress the mind with a sense of the greatness of God, and with the folly of attempting fully to comprehend the reason of what he does. Man is of a few days, and it is presumption in him to sit in judgment on the doings of one who is from eternity. We may here remark that the doctrine that there is an Eternal Being presiding over the universe, was a doctrine fully held by the speakers in this book - a doctrine far in advance of all that philosophy ever taught, and which was unknown for ages in the lands on which the light of revelation never shone.

God is great - He is omnipotent.
We know him not - He is unsearchable.
Neither can the number of his years be searched out - He is eternal.
These three propositions are an ample foundation for endless disquisition. As to paraphrase and comment, they need none in this place; they are too profound, comprehensive, and sublime.

Behold, God [is] great, (r) and we know [him] not, neither can the number of his years be searched out.
(r) Our infirmity hinders us so that we cannot attain the perfect knowledge of God.

Behold, God is great,.... In his power and might, in his wisdom and knowledge, in his truth and faithfulness, in his love, grace, and mercy, and that to admiration; and it is worthy of notice and attention, which the word "behold", prefixed hereunto, is expressive of: or is "much" or "many" (f); as he is in his persons: for though his essence is one, his persons are more, they are three, Father, Son, and Spirit; in his perfections, of which there is a fulness; in his thoughts, counsels, purposes? and decrees, which respect other persons and things; in his works of creation, providence, and grace, and in the blessings of his goodness, which are so many as not to be reckoned up;
and we know him not; God is to be known by the works of creation, and even by the very Heathen; though such is their inattention to them, that they are said not to know God; yea, even the wisest among them, by all their wisdom, knew not God, 1-Corinthians 1:21; for though they might know there was a God, they knew not who and what he was. God is known by his word among those who are favoured with a divine revelation of him, and especially by true believers in Christ, who know God in Christ, whom to know is life eternal; and yet these know but in part, there is no finding out the Almighty to perfection; God is not known clearly, fully, and perfectly, by any: or "we know it not"; the greatness of God; he is great, but we know not how great he is; his greatness is beyond all conception and expression;
neither can the number of his years be searched out; years are ascribed to God, after the manner of men, otherwise, properly speaking, they are not applicable to him; by which time is measured, and which belongs not to the eternal God; however, the number of his years in an eternity past, and of those to come, cannot be searched out and reckoned up: it requires no great skill in arithmetic to reckon up the years of the oldest man that ever lived; yea, the months, the days, the hours, and minutes, of his life may be counted; but the years of the Most High cannot; this is a phrase expressive of the eternity of him which is, and was, and is to come, and who from everlasting to everlasting is God. He was before the world was, as the creation of it out of nothing shows. Jehovah the Father had a Son, and he loved him before the foundation of the world, and all his people in him; he made an everlasting choice of them in him, before the world began; he made an everlasting covenant with them in him, and gave them grace in him as early as that; he set him up as Mediator from everlasting, from the beginning, or ever the earth was; and will be the everlasting and unchangeable portion of his people to all eternity. Cocceius thinks that these words are expressive of the constant love of God to the church, and the continuance of his kingdom in it; and of his most fixed purpose of love to men, and indefatigable care of them.
(f) Sept. "multus", Mercerus, Drusius.

(Job 37:13). God's greatness in heaven and earth: a reason why Job should bow under His afflicting hand.
know him not--only in part (Job 36:25; 1-Corinthians 13:12).
his years-- (Psalm 90:2; Psalm 102:24, Psalm 102:27); applied to Jesus Christ (Hebrews 1:12).

26 Behold, God is exalted-we know Him not entirely;
The number of His years, it is unsearchable.
27 For He draweth down the drops of water,
They distil as rain in connection with its mist,
28 Which the clouds do drop,
Distil upon the multitude of men.
29 Who can altogether understand the spreadings of the clouds,
The crash of His tabernacle?
The Waw of the quasi-conclusion in Job 36:26 corresponds to the Waw of the train of thought in Job 36:26 (Ges. 145, 2). מספּר שׁניו is, as the subject-notion, conceived as a nominative (vid., on Job 4:6), not as in similar quasi-antecedent clauses, e.g., Job 23:12, as an acc. of relation. שׂגּיא here and Job 37:23 occurs otherwise only in Old Testament Chaldee. In what follows Elihu describes the wondrous origin of rain. "If Job had only come," says a Midrash (Jalkut, 518), "to explain to us the matter of the race of the deluge (vid., especially Job 22:15-18), it had been sufficient; and if Elihu had only come to explain to us the matter of the origin of rain (מעשׂה ירידת גשׁמים), it had been enough." In Gesenius' Handwrterbuch, Job 36:27 is translated: when He has drawn up the drops of water to Himself, then, etc. But it is יגרע, not גּרע; and גּרע neither in Hebr. nor in Arab. signifies attrahere in sublime (Rosenm.), but only attrahere (root גר) and detrahere; the latter signification is the prevailing one in Hebr. (Job 15:8; Job 36:7). With כּי the transcendent exaltation of the Being who survives all changes of creation is shown by an example: He draws away (draws off, as it were) the water-drops, viz., from the waters that are confined above on the circle of the sky, which pass over us as mist and cloud (vid., Genesis, S. 107); and these water-drops distil down (זקק, to ooze, distil, here not in a transitive but an intransitive signification, since the water-drops are the rain itself) as rain, לאדו, with its mist, i.e., since a mist produced by it (Genesis 2:6) fills the expanse (רקיע), the downfall of which is just this rain, which, as Job 36:28 says, the clouds (called שׁחקים on account of its thin strata of air, in distinction from the next mist-circle) cause to flow gently down upon the multitude of men, i.e., far and wide over the mass of men who inhabit the district visited by the rain; both verbs are used transitively here, both נזל as Isaiah 45:8, and רעף, as evidently Proverbs 3:20. אף אם, Job 36:29, commences an intensive question: moreover, could one understand = could one completely understand; which certainly, according to the sense, is equivalent to: how much less (אף כּי). אם is, however, the interrogative an, and אף אם corresponds to האף in the first member of the double question, Job 34:17; Job 40:8. מפרשׂי are not the burstings, from פּרשׂ = פּרס, frangere, findere, but spreadings, as Ezekiel 27:7 shows, from פּרשׂ, expandere, Psalm 105:39, comp. supra on Job 36:9. It is the growth of the storm-clouds, which collect often from a beginning "small as a man's hand" (1-Kings 18:44), that is intended; majestic omnipotence conceals itself behind these as in a סכּה (Psalm 18:12) woven out of thick branches; and the rolling thunder is here called the crash (תּשׁאות, as Job 39:7, is formed from שׁוא, to rumble, whence also שׁואה, if it is not after the form גּולה, migration, exile, from שׁאה morf ,, vid., on Job 30:3) of this pavilion of clouds in which the Thunderer works.

Neither - He is eternal, as in his being, so in all his counsels; which therefore must be infinitely above the comprehension of short - lived men.