It is narrated from Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) that when Sayyiduna Umar bin al-Khattab (may Allah be pleased with him) accepted Islam, the Messenger of Allah (peace and blessings be upon him) struck him on the chest with his blessed hand three times, and he (peace and blessings be upon him) was saying: 'Allahumma akhrij ma fi sadrihi min ghillin wa abdilhu imanan' ((O Allah,) remove whatever rancour (or harshness) is in his chest and replace it with faith). He (peace and blessings be upon him) said these words three times. This hadith is sahih (authentic) with a sound (mustaqim) chain, but the two Shaykhs (Bukhari and Muslim) did not record it.