Law 12, Fouls and Misconduct / page 108 of the LOTG.
Denying a goal or an obvious goal-scoring opportunity Where a player denies the opposing team a goal or an obvious goal-scoring opportunity by a deliberate handball offence the player is sent off wherever the offence occurs. Where a player commits an offence against an opponent within their own penalty area which denies an opponent an obvious goal-scoring opportunity and the referee awards a penalty kick, the offender is cautioned if the offence was an attempt to play the ball; in all other circumstances (e.g. holding, pulling, pushing, no possibility to play the ball etc.) the offending player must be sent off.