Anas bin Malik narrated from Malik bin Sa’sa’ah – a man among his people – that :

the Prophet (ﷺ) of Allah said: “While I was at the House, between sleeping and being awake, I heard someone saying: “The one in the middle of the three.’ I was brought a vessel of gold containing Zamzam water, so my chest was split, to here.’” – Qatadah said: “I said to Anas: ‘What does that mean?’ He said: ‘To the lowest part of his stomach.’” – He said: “So my heart was removed, and washed with Zamzam water, then returned to its placed. Then I was filled with Faith and wisdom.”There is a long story with this Hadith.

حَدَّثَنَا مُحَمَّدُ بْنُ بَشَّارٍ، حَدَّثَنَا مُحَمَّدُ بْنُ جَعْفَرٍ، وَابْنُ أَبِي عَدِيٍّ، عَنْ سَعِيدِ بْنِ أَبِي عَرُوبَةَ، عَنْ قَتَادَةَ، عَنْ أَنَسِ بْنِ مَالِكٍ، عَنْ مَالِكِ بْنِ صَعْصَعَةَ، رَجُلٌ مِنْ قَوْمِهِ أَنَّ النَّبِيَّ صلى الله عليه وسلم قَالَ ‏"‏ بَيْنَمَا أَنَا عِنْدَ الْبَيْتِ بَيْنَ النَّائِمِ وَالْيَقْظَانِ إِذْ سَمِعْتُ قَائِلاً يَقُولُ أَحَدٌ بَيْنَ الثَّلاَثَةِ فَأُتِيتُ بِطَسْتٍ مِنْ ذَهَبٍ فِيهَا مَاءُ زَمْزَمَ فَشَرَحَ صَدْرِي إِلَى كَذَا وَكَذَا ‏"‏ ‏.‏ قَالَ قَتَادَةُ قُلْتُ يَعْنِي قُلْتُ لأَنَسِ بْنِ مَالِكٍ مَا يَعْنِي قَالَ ‏"‏ إِلَى أَسْفَلِ بَطْنِي فَاسْتُخْرِجَ قَلْبِي فَغُسِلَ قَلْبِي بِمَاءِ زَمْزَمَ ثُمَّ أُعِيدَ مَكَانَهُ ثُمَّ حُشِيَ إِيمَانًا وَحِكْمَةً ‏"‏ ‏.‏ وَفِي الْحَدِيثِ قِصَّةٌ طَوِيلَةٌ ‏.‏ قَالَ أَبُو عِيسَى هَذَا حَدِيثٌ حَسَنٌ صَحِيحٌ ‏.‏ وَقَدْ رَوَاهُ هِشَامٌ الدَّسْتَوَائِيُّ وَهَمَّامٌ عَنْ قَتَادَةَ ‏.‏ وَفِيهِ عَنْ أَبِي ذَرٍّ ‏.‏