What is the ruling when a pitcher wipes his hand on his mouth before coming to a set position?

When a pitcher wipes his hand on his mouth before coming to a set position, the correct ruling is that this action is considered a violation, leading to a balk. This is because touching the mouth can be perceived as an attempt to gain an unfair advantage by applying substances to the baseball, which contradicts the rules designed to maintain a level playing field. Therefore, the game officials must award the appropriate bases to the runners on base, as this action disrupts the integrity of the pitcher's motions and could be used to deceive the batter or runners. By enforcing this rule, the integrity of the game is upheld, ensuring that all actions during play are consistent with the established regulations.