If someone plays the harrowing does he target something and puts it on the chain? If so can I disposal order that card before it resolves?

Wrong use of 'pending' and 'finalized'

Yes, you can use Disposal Order to prevent a unit from being played by The Harrowing. Here is how the interaction works: 1. The Harrowing is played The Harrowing becomes a pending chain item, the game state becomes Closed, and The Harrowing goes through the process of finalization (unless something prevents this). When your opponent finalizes The Harrowing, they must choose a unit in their trash as a target. Because the spell's instructions require choosing a specific game object (the unit in the trash), that unit is targeted when The Harrowing is finalized on the chain. 2. You react with Disposal Order Because Disposal Order has the Reaction keyword, you can play it while The Harrowing is still on the chain waiting to resolve. You play Disposal Order and choose the unit your opponent targeted with The Harrowing (and up to two other cards) from their trash. These cards are then recycled to the bottom of their owner's deck. 3. Resolution The chain resolves in reverse order (LIFO). Disposal Order resolves first, and those cards are moved to the deck. Next, The Harrowing attempts to resolve. Because the unit it was targeting is no longer in the trash (it has changed zones to the deck), the target is now illegal. Per Rule 359.3.e.1, the spell resolves anyway, but because its instruction cannot be executed (there is no valid unit to play), it has no effect on the board. Summary: By reacting to The Harrowing with Disposal Order, you move the intended unit out of the trash before The Harrowing can pull it into play, effectively countering the spell's primary effect.