וכל לבבות יראוך וכל קרב וכליות יזמרו לשמך
All hearts will fear you and all "insides" will sing to you. [From the "Nishmas" prayer]
A person should have such awe and reverence for Hashem that he sings to Him on the inside but he can't get the words out because of the overwhelming awe. וכל קרב וכליות יזמרו לשמך.
[Baal HaTanya - Drasha for Shmini Atzeres]
