Sahih al-Bukhari 51
Book 2: Belief · Hadith 44
Hadith text
Narrated 'Abdullah bin 'Abbas: I was informed by Abu Sufyan that Heraclius said to him, "I asked you whether they (followers of Muhammad) were increasing or decreasing. You replied that they were increasing. And in fact, this is the way of true Faith till it is complete in all respects. I further asked you whether there was anybody, who, after embracing his (the Prophets) religion (Islam) became displeased and discarded it. You replied in the negative, and in fact, this is (a sign of) true faith. When its delight enters the heart and mixes with them completely, nobody can be displeased with it
Abdullah bin Abbas (رضی اللہ عنہما) bataate hain ke Abu Sufyan ne unhe bataya ke Heraclius ne unse kaha: "Maine tumse poocha tha ke woh (Muhammad ke pairokar) badh rahe hain ya kam ho rahe hain, tumne kaha badh rahe hain — aur yehi sachche iman ka tareeqa hai jab tak mukammal na ho jaye. Maine tumse yeh bhi poocha tha ke koi uska deen (Islam) qubool karne ke baad naraz hokar chhod deta hai, tumne 'nahi' kaha — aur yeh bhi sachche iman ki nishani hai. Jab iski khushi dilon mein rach jaati hai, to koi usse naraz nahi hota."
Sahih al-Bukhari 51 · Book 2, Hadith 44