put (one's) hand on (one's) heart
(redirected from put hand on heart)put (one's) hand on (one's) heart
To swear that something is completely truthful, genuine, or sincere. I can put my hand on my heart and say that we have only ever acted in the best interests of our customers.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.