It is narrated from Hazrat Aisha (may Allah be pleased with her) that the Prophet (peace and blessings be upon him) used to say to her: "When you are angry, I can tell that you are angry, and when you are pleased, I can tell that as well. When you are angry, you say 'No, by the Lord of Ibrahim,' and when you are pleased, you say 'No, by the Lord of Muhammad.'"