No man ought to looke a given ...

No man ought to looke a given horse in the mouth.
 John Heywood

Quotes from the same author

All's well that ends well.
 John Heywood
Never look a gift horse in the mouth.
 John Heywood
God never sends the mouth but he sendeth meat.
 John Heywood
Prove your friend ere you have need, but in deed A friend is never known till a man have need.
 John Heywood