75 Heb “all the work of God.”
76 Heb “the work that is done.”
77 Heb “under the sun.”
78 Heb “his”; the referent (man, in a generic sense) has been specified in the translation as the adjective “human” for clarity.
79 Heb “find.”
80 The term “it” does not appear in the Hebrew text, but is supplied in the translation for smoothness.
81 The particle אִם (’im, “even if”) introduces the protasis in a real conditional clause (“If a wise man …”); see §38.2d; R. J. Williams, Hebrew Syntax, 74, §453.
82 The imperfect tense verb יֹאמַר (yo’mar, “to say”) functions in a modal sense, denoting possibility (see §31.4e; R. J. Williams, Hebrew Syntax, 31, §169).
83 Heb “he cannot find”; or “he does not find.”
84 The term “it” does not appear in the Hebrew text, but is an implied direct object and has been supplied in the translation for smoothness and stylistic reasons.

In other versions

ESVEnglish Standard Version

then I saw all the work of God, that man cannot find out the work that is done under the sun. However much man may toil in seeking, he will not find it out. Even though a wise man claims to know, he cannot find it out.

NIVNew International Version (2011)

then I saw all that God has done. No one can comprehend what goes on under the sun. Despite all their efforts to search it out, no one can discover its meaning. Even if the wise claim they know, they cannot really comprehend it.

CSBChristian Standard Bible

I observed all the work of God and concluded that a person is unable to discover the work that is done under the sun. Even though a person labors hard to explore it, he cannot find it; even if a wise person claims to know it, he is unable to discover it.

NLTNew Living Translation

I realized that no one can discover everything God is doing under the sun. Not even the wisest people discover everything, no matter what they claim.

LEBThe Lexham English Bible

Then I saw all the work of God—man is not able to discover the work that is done under the sun. Although man may toil in seeking, he cannot find it. Even if a wise man claims that he knows it, he cannot find it.

KJV 1900King James Version

Then I beheld all the work of God, that a man cannot find out the work that is done under the sun: because though a man labour to seek it out, yet he shall not find it; yea further; though a wise man think to know it, yet shall he not be able to find it.

Public Domain