Sahih Muslim 1662
صحيح مسلم#1662SahihUrwa reported 'A'isha to be sayidg:I have never seen the Messenger of Allah (ﷺ) observing the supererogatory prayer of the forenoon, but I observed it. And if the Messenger of Allah (ﷺ) abandoned any act which he in fact loved to do, it was out of fear that if the people practised it constantly, it might become obligatory for them
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Every narration in Sahih Muslim is accepted as Sahih (authentic) by the established status of the book.
In-book reference: 6:92