When saying the Pledge of Allegiance to our country, one of the appropriate signs of respect is to place your right hand over your left breast, thus covering your heart.
Young children can be taught to do this and can master this protocol quickly. Thus, when an adult instructs them to place their hand over their heart, a roomful of school-aged youngsters can promptly respond correctly.
Your hand is not the same part of your body as your heart is. Your heart is within your body. Your hands are appendages on the outside of your body.
Since this is NOT advanced rocket science, it really is a puzzle how many people apparently cannot discern the difference between these two statements:
Singing and making melody with your heart.
Singing and making melody with your hands.
One of these statements is found in the New Testament in Ephesians 5:19; one is not.
When it comes to praising God in worship, do you know the difference between your heart and your hands?