One man - One whose good qualities quite satisfy our expectation. Compare the expression “one among a thousand” (marginal reference).
A woman - The number of Solomon’s wives and concubines 1 Kings 11:3 was a thousand.
Related Commentaries of Ecclesiastes 7:28
Ecclesiastes 7:28
28 Which yet my soul seeketh, but I find not: one man among a thousand have I found; but a woman among all those have I not found.