“If their defences are strong, it is because you have not used the weapon of mercy.”
‘Were you rough and hard of heart they would have dispersed from round about you.’ (3:159) is the battlecry of Da’wa. ‘Allah gives through gentleness what He does not give through roughness’ (Hadith). The Holy Prophet ﷺ transformed his hard-hearted people in only twenty-three years. He took them from the many to the One, from vendetta to the Sacred Law, from despair over death to the certainty of eternal life. In this he was ‘sent only as a mercy to the worlds’ (21:107). But without his mercy this mercy would have been marked ‘Return to Sender’.
In our tradition the first hadith to be studied is this: ‘Those who show mercy shall be shown mercy by the All-Merciful.’
Mercy is the divine nature: ‘Say: to whom doth everything in the heavens and the earth belong? Say: unto Allah. He has written mercy upon Himself’ (6:12).
The Messenger of Allah ﷺ kissed his grandon al-Hasan Radhiallahu anhu while al-Aqra’ ibn Habis of B. Tamim was sitting nearby. Al-Aqra’ said: ‘I have ten children and have never kissed any of them.’ Allah’s Messenger ﷺ looked at him and said: ‘He who does not show mercy, to him shall mercy not be shown.’
‘Allah made mercy to be of one hundred parts. He withheld ninety-nine, and sent down one part to the earth. It is from that part that creatures show mercy one to another, such as a mare’s lifting of her hoof from her foal, fearful that she might harm him.’ (Hadith)
Through the display of mercy and gentleness, the scholars melted the heart of the Mongol king Oljeitu, so that he came to Islam and became one of its greatest champions.
(Source: Commentary on the Eleventh Contentions, Contention No. 96, Pgs. 167-168)