A man from his people reported that the Prophet ﷺ said, "While I was at the House, in a state between sleep and wakefulness, I heard a voice saying, 'One of the three.' Then a basin of gold containing the water of Zamzam was brought to me, and my chest was opened down to such and such a place."Qatada said, I asked Anas bin Malik, "What does he mean?"He replied, "Down to the lower part of his belly.""Then my heart was extracted and washed with the water of Zamzam, then it was returned to its place and filled with faith and wisdom."The hadith contains a long story.
حدثنا محمد بن بشار حدثنا محمد بن جعفر وابن أبي عدي عن سعيد بن أبي عروبة عن قتادة عن أنس بن مالك
رجل من قومه أن النبي ﷺ قال بينما أنا عند البيت بين النائم واليقظان إذ سمعت قائلا يقول أحد بين الثلاثة فأتيت بطست من ذهب فيها ماء زمزم فشرح صدري إلى كذا وكذا قال قتادة قلت لأنس بن مالك ما يعني قال إلى أسفل بطني فاستخرج قلبي فغسل قلبي بماء زمزم ثم أعيد مكانه ثم حشي إيمانا وحكمة وفي الحديث قصة طويلة
Agreed upon (by Bukhari and Muslim). Muslim also related it in the Book of Faith, chapter on the Night Journey of the Messenger of Allah ﷺ to the heavens and the prescribing of the prayers, no. 164, from the hadith of Muhammad bin Abu Adi, and Bukhari related it, no. 3207, from the hadith of Saeed bin Abu Urwa, with the same wording.It also contains a report from Abu Dharr [Bukhari, no. 349, and Muslim, no. 163, at greater length].