Ecclesiastes 1:17
And I applied my heart to the knowledge of wisdom, and to the knowledge of madness and folly: I perceived that this also is a striving after the wind.
Ecclesiastes 2:3
I searched in my heart how to cherish my flesh with wine, while practising my heart with wisdom; and how to lay hold on folly, till I should see what was that good for the children of men which they should do under the heavens all the days of their life.
Ecclesiastes 1:13-14
And I applied my heart to seek and search out by wisdom concerning all that is done under the heavens: this grievous occupation hath God given to the children of men to weary themselves therewith.
Ecclesiastes 2:10-12
And whatsoever mine eyes desired I kept not from them: I withheld not my heart from any joy; for my heart rejoiced in all my labour, and this was my portion from all my labour.
Ecclesiastes 7:23-25
All this have I tried by wisdom: I said, I will be wise; but it was far from me.
1 Thessalonians 5:21
but prove all things, hold fast the right;