Assalamualaikum ustaz. There are some who teach that during the incident where the Prophet PBUH’s chest was cut open, not Zamzam water but the snow was used to wash the heart of the Prophet PBUH. Furthermore, the angel that cut open the chest of the Prophet PBUH wasn’t mentioned. Is this true? Hope for an explanation.
Waalaikumussalam wrt. wbt.,
Alhamdulillah, praise and gratitude to Allah SWT for His countless blessings for us all. Praise and salutations to our beloved Prophet Muhammad PBUH, his family, companions, and all those who follow his footsteps until the Final day.
First of all, the story is sahih as it is described in a sahih hadith. The hadith is narrated by Imam Muslim RA in his sahih and it is narrated by Anas bin Malik RA, he said:
أَتَاهُ جِبْرِيلُ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ وَهُوَ يَلْعَبُ مَعَ الْغِلْمَانِ، فَأَخَذَهُ فَصَرَعَهُ، فَشَقَّ عَنْ قَلْبِهِ، فَاسْتَخْرَجَ الْقَلْبَ، فَاسْتَخْرَجَ مِنْهُ عَلَقَةً، فَقَالَ: هَذَا حَظُّ الشَّيْطَانِ مِنْكَ، ثُمَّ غَسَلَهُ فِي طَسْتٍ مِنْ ذَهَبٍ بِمَاءِ زَمْزَمَ، ثُمَّ لَأَمَهُ، ثُمَّ أَعَادَهُ فِي مَكَانِهِ، وَجَاءَ الْغِلْمَانُ يَسْعَوْنَ إِلَى أُمِّهِ – يَعْنِي ظِئْرَهُ – فَقَالُوا: إِنَّ مُحَمَّدًا قَدْ قُتِلَ، فَاسْتَقْبَلُوهُ وَهُوَ مُنْتَقِعُ اللَّوْنِ “، قَالَ أَنَسٌ: «وَقَدْ كُنْتُ أَرَى أَثَرَ ذَلِكَ الْمِخْيَطِ فِي صَدْرِهِ
“Gabriel came to the Messenger of Allah (ﷺ) while he was playing with his playmates. He took hold of him and lay him prostrate on the ground and tore open his breast and took out the heart from it and then extracted a blood-clot out of it and said: That was the part of Satan in thee. And then he washed it with the water of Zamzam in a golden basin and then it was joined together and restored to it place. The boys came running to his mother, i. e. his nurse, and said: Verily Muhammad has been murdered. They all rushed toward him (and found him all right) His color was changed, Anas said. I myself saw the marks of needle on his breast.” 
Coming back to the above question, there are two issues:
First: The name of the angle and the number of times
In this issue, scholars have differing opinions as to how many times the chest of Rasullullah PBUH was cut open. Ibn Hajar al-Asqalani said: “Some rejects the incident of the chest getting cut open on the night of Isra’. They said, it only happened once when the Prophet PBUH was still young in the village of Bani Sa’d. This is not rejected, for there are several narrations and the cutting open of the chest also happen when the Prophet PBUH was appointed as the Messenger as stated in the narration of Abu Nuaim in al-Dala’il. I summarized it as the following:
- The first time is when he was still young at the age of 4 years old. Gabriell came and lay him on the ground and cut open his chest. This is narrated by Muslim in his Sahih from Anas bin Malik.
- When he was appointed as the Messenger as stated in the narration of Abu Nuaim in al-Dala’il.
- In the incident of Isra’ and Mi’raj and this is thabit in Sahih Bukhari and Muslim and others such as the narration of Anas bin Malik from Malik bin Sa’sa’ah and others.
According to the above narrations, it shows that Gabriel was the angel that cuts open the Prophet PBUH’s chest.
Second: The water used
According to some narrations, the type of water isn’t mentioned. However, in other narrations, Zamzam water was stated to be used.
Thus, I’m inclined to the opinion which states that it is washed with Zamzam water, for the narration of Zamzam water is ithbat and the maxim states that ithbat is prioritized over denial.
Please refer to muktabar books such as Fath al-Bari, al-Sahih min Sirat al-Nabi al-A’zam, al-Tabaqat by Ibn Sa’d, Dala’il al-Nubuwwah by al-Baihaqi and others. May Allah SWT grant us all understanding in seeking for sahih and true facts, amin.
 Narrated by Muslim (162)