Qatila bint Saifi Juhaniya (may Allah be pleased with her) narrated: A Jewish scholar came to the Messenger of Allah (peace be upon him), then the narrator reported the hadith similar to the previous one, and added this: Upon both matters, he said: Subhan Allah! Subhan Allah! (an expression of amazement) What is that? And he said: "Whoever says, 'Whatever Allah wills,' then he should say between the two: 'Then as you will.'"
Hadith Referenceمسند اسحاق بن راهويه / كتاب الايمان / 70