Grappling Block( Oriental Adventures, p. 63)
You can catch and pin an opponent's weapon with your bare hands.
You must have both hands free or be holding weapons designed to catch other weapons (such as the sai or jitte) to use this feat. Once per round when you would normally be hit by a melee weapon, you may make a special disarm attempt against your opponent. This attempt counts against your allowed attacks of opportunity this round. You make an opposed attack roll (with your unarmed strike, sai, or jitte) against the attack roll that hit you. The opponent's attack roll is not modified by the size of the weapon. If you succeed, you grab the weapon away from your opponent (if you are unarmed) or knock the weapon to the ground (if you are armed). You may only use this feat against weapons up to two sizes larger than you.