Bible: Labour Laboured

Repeated words found across different books in the Bible (KJV):
Eccl 2:11
Then I looked on all the works that my hands had wrought, and on the labour that I had laboured to do: and, behold, all was vanity and vexation of spirit, and there was no profit under the sun.

Eccl 2:19
And who knoweth whether he shall be a wise man or a fool? yet shall he have rule over all my labour wherein I have laboured, and wherein I have shewed myself wise under the sun. This is also vanity.

Eccl 2:21
For there is a man whose labour is in wisdom, and in knowledge, and in equity; yet to a man that hath not laboured therein shall he leave it for his portion. This also is vanity and a great evil.

Eccl 2:22
For what hath man of all his labour, and of the vexation of his heart, wherein he hath laboured under the sun?

John 4:38
I sent you to reap that whereon ye bestowed no labour: other men laboured, and ye are entered into their labours.

Rom 16:12
Salute Tryphena and Tryphosa, who labour in the Lord. Salute the beloved Persis, which laboured much in the Lord.