У скупого в мороз снега не выпросишь

You cannot get help from an uncharitable or greedy man

Var.: Среди зимы льда не выпросишь у кумы

Cf: Ask a kite for a feather and she will say she has but just enough to fly with (Br.). If he had the 'flu, he wouldn't give you a sneeze (Br.). You cannot get blood from (out of) a stone (Am., Br.). You cannot get blood from a turnip (Am.)