Verses with the word doer in the Old Testament (4 verses):

Genesis 39:22
And the keeper of the prison committed to Joseph's hand all the prisoners that were in the prison; and whatsoever they did there, he was the doer of it.

2 Samuel 3:39
And I am this day weak, though anointed king; and these men the sons of Zeruiah be too hard for me: the LORD shall reward the doer of evil according to his wickedness.

Psalms 31:23
O love the LORD, all ye his saints: for the LORD preserveth the faithful, and plentifully rewardeth the proud doer.

Proverbs 17:4
A wicked doer giveth heed to false lips; and a liar giveth ear to a naughty tongue.