Leave no stone ...

Leave no stone unturned.
Leave no stone unturned.

More phrases

If one does not know to which port one is sailing, no wind is favorable.
What a distressing contrast there is between the radiant intelligence of the child and the feeble mentality of the average adult.
We are masters of the unsaid words, but slaves of those we let slip out.
I have always found that mercy bears richer fruits than strict justice.
A lie gets halfway around the world before the truth has a chance to get its pants on.

Quotes from the same author

Friends show their love in times of trouble, not in happiness.
Along with success comes a reputation for wisdom.
One loyal friend is worth ten thousand relatives.
Life has no blessing like a prudent friend.
Cleverness is not wisdom.