My opponent attacks with Messengers of Joppa and I block with Foreign Wives with an empty hand. I play Swift horses to interrupt, D3, and play Moses kills the Egyptian. my opponent uses Gifts to allow himself to draw 3, before realizing that doing so would trigger Wives protection. He uses the Gamaliel's Speech he just drew to negate horses. The problem arises in that if horses is negated then he doesn't get to draw off gifts. No draw from gifts means no GS.
Am I correct in remembering that you can't indirectly negate yourself?