Sahih Muslim 2805
Sahih Muslim · Book 52: Characteristics of the Day of Judgment, Paradise, and Hell · The Disbeliever Seeking Ransom With An Earthful Of Gold
Anas reported this hadlth through another chain of transmitters and the words are:
وَحَدَّثَنَا عَبْدُ بْنُ حُمَيْدٍ ، حَدَّثَنَا رَوْحُ بْنُ عُبَادَةَ ، ح وَحَدَّثَنِي عَمْرُو بْنُ زُرَارَةَ ، أَخْبَرَنَا عَبْدُ الْوَهَّابِ، - يَعْنِي ابْنَ عَطَاءٍ - كِلاَهُمَا عَنْ سَعِيدِ بْنِ أَبِي عَرُوبَةَ ، عَنْ قَتَادَةَ ، عَنْ أَنَسٍ ، عَنِ النَّبِيِّ صلى الله عليه وسلم بِمِثْلِهِ غَيْرَ أَنَّهُ قَالَ " فَيُقَالُ لَهُ كَذَبْتَ قَدْ سُئِلْتَ مَا هُوَ أَيْسَرُ مِنْ ذَلِكَ " .
" It would be said to him: You have told a lie; what had been demanded from you was quite easier than this (the belief in the Oneness of Allah)."