It is narrated from Hazrat Anas (may Allah be pleased with him) with reference to Ubayy bin Ka'b (may Allah be pleased with him) that the Noble Prophet (peace and blessings be upon him) said: During the time when I was in Makkah Mukarramah, one day the roof of my house was opened and from there Hazrat Jibreel (peace be upon him) descended. He split open my chest, washed it with the water of Zamzam, then brought a tray filled with wisdom and faith and poured it into my chest, and then closed it up.