don't rush when in doubt; look before you leap
Proverb advising against hasty action when uncertain; often contrasted with 善は急げ (strike while the iron is hot).
See also: 善は急げ
As the saying goes, 'Don't rush when in doubt,' so let's gather more information before deciding.
A Japanese proverb. The exact origin is uncertain, but it is traditionally contrasted with 善は急げ.