Sahih al-Bukhari 6423
Sahih al-Bukhari · Book 81: To make the Heart Tender (Ar-Riqaq) · The deed which is done seeking Allah's Countenance
Narrated `Utban bin Malik Al-Ansari:
قَالَ سَمِعْتُ عِتْبَانَ بْنَ مَالِكٍ الأَنْصَارِيَّ ، ثُمَّ أَحَدَ بَنِي سَالِمٍ قَالَ غَدَا عَلَىَّ رَسُولُ اللَّهِ صلى الله عليه وسلم فَقَالَ " لَنْ يُوَافِيَ عَبْدٌ يَوْمَ الْقِيَامَةِ يَقُولُ لاَ إِلَهَ إِلاَّ اللَّهُ. يَبْتَغِي بِهِ وَجْهَ اللَّهِ، إِلاَّ حَرَّمَ اللَّهُ عَلَيْهِ النَّارَ " .
who was one of the men of the tribe of Bani Salim: Allah's Messenger (ﷺ) came to me and said, "If anybody comes on the Day of Resurrection who has said: La ilaha illal-lah, sincerely, with the intention to win Allah's Pleasure, Allah will make the Hell-Fire forbidden for him."