Scenario: I have two blood scrivener in the battlefield and no cards in hand.

Blood Scrivener
Creature - Zombie Wizard
If you would draw a card while you have no cards in hand, instead draw two cards and lose 1 life.
2/1

Then, I draw a card.

1. Blood Scrivener A triggers, replaces the "draw a card" by "draw a card. draw a card. lose 1 life"
2. Blood Scrivener B triggers, replaces "draw a card. draw a card. lose 1 life" for "draw a card. draw a card. lose 1 life. draw a card. lose 1 life."

If the above steps are correct, what rule prevents the following steps to take place?

3. Blood Scrivener A triggers again, replaces "draw a card. draw a card. lose 1 life. draw a card. lose 1 life" for "draw a card. draw a card. lose 1 life. draw a card. lose 1 life. draw a card. lose 1 life"
4. Blood Scrivener B triggers again, continuing the infinite loop.