The proverb

He that will not when he may, when he will he shall have nay

basically states that one should not be too demanding when it comes to choosing.

According to Wikipedia:

as the ancient proverb proposes

 

^{Wikipedia, The Heron and the Fish, 02:07, 16 September 2017}

it describes it as ancient but there's nothing I can find that links this proverb to a source of some sort. The footnote only redirects me to this broken link.

The proverb

He that will not when he may, when he will he shall have nay

basically states that one should not be too demanding when it comes to choosing.

According to Wikipedia:

as the ancient proverb proposes

^{Wikipedia, The Heron and the Fish, 02:07, 16 September 2017}

it describes it as ancient but there's nothing I can find that links this proverb to a source of some sort. The footnote only redirects me to this broken link.