Wisdom behind cutting chest open:

Explaining the reasons for cutting the blessed chest open of the Beloved Rasool صَلَّى اللهُ تَعَالٰى عَلَيْهِ وَاٰلِهٖ وَسَلَّم Shaykh-ul-Hadees ‘Allamah Maulana Abdul Mustafa A’zami رَحْمَةُ اللهِ تَعَالٰی عَلَيْه has said: The blessed chest of the Beloved Rasool صَلَّى اللهُ تَعَالٰى عَلَيْهِ وَاٰلِهٖ وَسَلَّم was cut open four times. First time, it occurred when he صَلَّى اللهُ تَعَالٰى عَلَيْهِ وَاٰلِهٖ وَسَلَّم was in the house of Haleemah Sadiyyah رَضِیَ اللهُ تَعَالٰی عَنْهَا. It was aimed at protecting him from the evil thoughts that attract children to games and mischievous activities. Second time, when the Beloved Rasool صَلَّى اللهُ تَعَالٰى عَلَيْهِ وَاٰلِهٖ وَسَلَّم was 10 years old his blessed chest was cut open so that he صَلَّى اللهُ تَعَالٰى عَلَيْهِ وَاٰلِهٖ وَسَلَّم would remain unaffected and unharmed by the risks of the desires of youth. Third time, his blessed chest was cut open in the cave Hira where his blessed heart was filled with Noor and peace so that he صَلَّى اللهُ تَعَالٰى عَلَيْهِ وَاٰلِهٖ وَسَلَّم could bear the great burden of the revelation from the Almighty. Fourth time, on the night of Mi’raaj, his blessed chest was cut open and filled with the treasure of Noor and Divine wisdom so that his blessed heart may have the magnitude and capability to bear the Tajalliyaat of Divine sight and the greatness of Divine conversation. (Seerat-e- Mustafa, pp. 79-80)

صَلُّوۡا عَلَى الۡحَبِيۡب                                  صَلَّى اللّٰهُ تَعَالٰى عَلٰى مُحَمَّد

The blessed conveyance of the Beloved Rasool صَلَّى اللهُ تَعَالٰى عَلَيْهِ وَاٰلِهٖ وَسَلَّم:

Dear Islamic brothers! Another aspect of the greatness of Mustafa صَلَّى اللهُ تَعَالٰى عَلَيْهِ وَاٰلِهٖ وَسَلَّم in the event of Mi’raaj is that for this great and glorious journey, extremely great Heavenly conveyance was selected for the Beloved Rasool صَلَّى اللهُ تَعَالٰى عَلَيْهِ وَاٰلِهٖ وَسَلَّم. Sayyiduna Anas bin Malik رَضِىَ اللهُ تَعَالٰی عَـنْهُ has narrated that the Beloved Rasool صَلَّى اللهُ تَعَالٰى عَلَيْهِ وَاٰلِهٖ وَسَلَّم said: Buraaq [whose name was Jarood.] was brought to me which was extremely white and tall quadruped. It was bigger than a donkey and smaller than a mule. It could place its hooves at the farthest boundary of its gaze. (Muslim, pp. 87, Hadees, 411) 

Mufti Ahmad Yar Khan رَحْمَةُ اللهِ تَعَالٰی عَلَيْه has said: Here [in Hateem-e-Ka’bah] blessed chest was cut open; Ghusl was given with Kausar and Zam Zam; the Beloved Rasool صَلَّى اللهُ تَعَالٰى عَلَيْهِ وَاٰلِهٖ وَسَلَّم was made a bridegroom after being adorned