'Travail' in the Bible

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.

For all his days are sorrows, and his travail sadness; even at night his heart hath not lain down; this also is vanity.

For to a man who is good before Him, He hath given wisdom, and knowledge, and joy; and to a sinner He hath given travail, to gather and to heap up, to give to the good before God. Even this is vanity and vexation of spirit.

I have seen the travail that God hath given to the sons of man to be humbled by it.

There is one, and there is not a second; even son or brother he hath not, and there is no end to all his labour! His eye also is not satisfied with riches, and he saith not, 'For whom am I labouring and bereaving my soul of good?' This also is vanity, it is a sad travail.