Benefactor's Draught

• WWizards of the Coast2016-11-08
  Official Ruling
  You must cast Benefactor’s Draught before blockers are declared in order to draw any cards from its delayed triggered ability.
• WWizards of the Coast2016-11-08
  Official Ruling
  If multiple copies of Benefactor’s Draught resolve in one turn, each creates a delayed triggered ability and each will trigger when its condition is met.
• WWizards of the Coast2016-11-08
  Official Ruling
  Each player will have a chance to cast instants and activate abilities after Benefactor’s Draught’s delayed triggered abilities have resolved, before combat damage is dealt.

Rulings via Scryfall