The right hand – Ask the Rabbi
Q. Why does Psalm 137 (“By the Waters of Babylon”) say, “Let my right hand wither”? Why not the left hand?
A. Biblical thinking regarded the right hand as stronger and more normative.
Psalm 16 says “Because God is at my right hand I shall not be moved”. God Himself was thought of metaphorically as right-handed; the Song of the Sea (Ex. 15) says, “Your right hand, O Lord, is glorious”.
Being left-handed was regarded as a handicap. Not only in Biblical thinking but in many cultures. That is why the Latin word for left is sinister. The right is dexter: if you are dexterous you are seen as having a lot of right-handed skills.