keep your breath to cool your porridge

keep your breath to cool your porridge

Focus on yourself and your life, rather than other people's lives and issues. Lady Martha, I strongly suggest that you keep your breath to cool your porridge, rather than intruding upon these affairs.
See also: breath, cool, keep, porridge
References in classic literature ?
Darcy, "There is a fine old saying, which everybody here is of course familiar with: 'Keep your breath to cool your porridge'; and I shall keep mine to swell my song."