Silsilat al-Ahadith al-Sahihah

Sayyidah Qutaylah bint Safi Juhaniyyah (may Allah be pleased with her) says: A Jewish scholar came to the Messenger of Allah (peace and blessings be upon him) and said: O Muhammad! You are the best of people, but if only you did not commit shirk? The Prophet (peace and blessings be upon him) said: “Subhan Allah! (How astonishing!) How is that?” He said: When you swear an oath, you say: By the Ka‘bah. The Prophet (peace and blessings be upon him) remained silent for a while and then said: “This man has spoken the truth. Now, whoever swears an oath should swear by the Lord of the Ka‘bah (and not by the Ka‘bah itself).” He then said: O Muhammad (peace and blessings be upon him)! You are very good people, but if only you did not set up equals with Allah! The Prophet (peace and blessings be upon him) said: Subhan Allah! How is that? He said: You say: Whatever Allah wills and you will. The Messenger of Allah (peace and blessings be upon him) remained silent for a while, then said: “This man has spoken the truth. If anyone says ‘Masha Allah’, he should say «ثُم شئت» (i.e., whatever Allah wills and then you will).”