Sahih Muslim Book - 1, Hadith - 349

و حَدَّثَنِي عَبْدُ اللَّهِ بْنُ الرُّومِيِّ حَدَّثَنَا النَّضْرُ بْنُ مُحَمَّدٍ حَدَّثَنَا عِكْرِمَةُ وَهُوَ ابْنُ عَمَّارٍ حَدَّثَنَا يَحْيَى حَدَّثَنَا أَبُو سَلَمَةَ عَنْ أَبِي هُرَيْرَةَ قَالَ قَالَ لِي رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ لَا يَزَالُونَ يَسْأَلُونَكَ يَا أَبَا هُرَيْرَةَ حَتَّى يَقُولُوا هَذَا اللَّهُ فَمَنْ خَلَقَ اللَّهَ قَالَ فَبَيْنَا أَنَا فِي الْمَسْجِدِ إِذْ جَاءَنِي نَاسٌ مِنْ الْأَعْرَابِ فَقَالُوا يَا أَبَا هُرَيْرَةَ هَذَا اللَّهُ فَمَنْ خَلَقَ اللَّهَ قَالَ فَأَخَذَ حَصًى بِكَفِّهِ فَرَمَاهُمْ ثُمَّ قَالَ قُومُوا قُومُوا صَدَقَ خَلِيلِي صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ.

It was narrated that Abu Hurairah said: "The Messenger of Allah (s.a.w) said to me: 'They will keep on asking you, O Abu Hurairah, until they say: This is Allah, but who created Allah?' " He (Abu Hurairah) said: "While I was in the Masjid, some Bedouin people came to me and said: 'O Abu Hurairah, this is Allah, but who created Allah?"' He took some pebbles in his hand and threw at them, then he said: "Go away, go away! My close friend (s.a.w) spoke the truth."