The Clue "Do ____ others ..."
The Answer UNTO
The phrase "Do unto others" is part of a well-known saying that encourages treating people the way you want to be treated. The word "unto" fits perfectly in this phrase, as it connects the action of doing with the people involved. This answer captures the essence of the saying, emphasizing kindness and respect in our interactions. Overall, "unto" is the right word to complete this popular expression.