New International Version
I applied my mind to study and to explore by wisdom all that is done under the heavens. What a heavy burden God has laid on mankind!

American Standard Version
And I applied my heart to seek and to search out by wisdom concerning all that is done under heaven: it is a sore travail that God hath given to the sons of men to be exercised therewith.

Berean Study Bible
And I set my mind to seek and explore by wisdom all that is done under heaven. What a heavy burden God has laid upon the sons of men to occupy them!

Douay-Rheims Bible
And I proposed in my mind to seek and search out wisely concerning all things that are done under the sun. This painful occupation hath God given to the children of men, to be exercised therein.

English Revised Version
And I applied my heart to seek and to search out by wisdom concerning all that is done under heaven: it is a sore travail that God hath given to the sons of men to be exercised therewith.

King James Bible
And I gave my heart to seek and search out by wisdom concerning all things that are done under heaven: this sore travail hath God given to the sons of man to be exercised therewith.

World English Bible
I applied my heart to seek and to search out by wisdom concerning all that is done under the sky. It is a heavy burden that God has given to the sons of men to be afflicted with.

Young's Literal Translation
And I have given my heart to seek and to search out by wisdom concerning all that hath been done under the heavens. It is a sad travail God hath given to the sons of man to be humbled by it.

Ecclesiastes 1:13 Additional Translations ...