"I swear to you, then," said MacIan, after a pause. "I swear to you that nothing shall come between us. I swear to you that nothing shall be in my heart or in my head till our swords clash together. I swear it by the God you have denied, by the Blessed Lady you have blasphemed; I swear it by the seven swords in her heart. I swear it by the Holy Island where my fathers are, by the honour of my mother, by the secret of my people, and by the chalice of the Blood of God."
The atheist drew up his head. "And I," he said, "give my word."

The Ball and the Cross (1909), part II: "The Religion of the Stipendiary Magistrate", last paragraphs