كتاب البر والصلة والآداب
45  
The Book of Virtue, Enjoining Good Manners, and Joining of the Ties of Kinship
(29)
Chapter: The Abhorrence Of Lying, And The Goodness And Virtue Of Honesty
(29)
باب قُبْحِ الْكَذِبِ وَحُسْنِ الصِّدْقِ وَفَضْلِهِ ‏‏
Sahih Muslim 2607 c

'Abdullah reported Allah's Messenger (ﷺ) as saying:

It is obligatory for you to tell the truth, for truth leads to virtue and virtue leads to Paradise, and the man who continues to speak the truth and endeavours to tell the truth is eventually recorded as truthful with Allah, and beware of telling of a lie for telling of a lie leads to obscenity and obscenity leads to Hell-Fire, and the person who keeps telling lies and endeavours to tell a lie is recorded as a liar with Allah.
حَدَّثَنَا مُحَمَّدُ بْنُ عَبْدِ اللَّهِ بْنِ نُمَيْرٍ، حَدَّثَنَا أَبُو مُعَاوِيَةَ، وَوَكِيعٌ، قَالاَ حَدَّثَنَا الأَعْمَشُ، ح وَحَدَّثَنَا أَبُو كُرَيْبٍ، حَدَّثَنَا أَبُو مُعَاوِيَةَ، حَدَّثَنَا الأَعْمَشُ، عَنْ شَقِيقٍ، عَنْ عَبْدِ اللَّهِ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏ "‏ عَلَيْكُمْ بِالصِّدْقِ فَإِنَّ الصِّدْقَ يَهْدِي إِلَى الْبِرِّ وَإِنَّ الْبِرَّ يَهْدِي إِلَى الْجَنَّةِ وَمَا يَزَالُ الرَّجُلُ يَصْدُقُ وَيَتَحَرَّى الصِّدْقَ حَتَّى يُكْتَبَ عِنْدَ اللَّهِ صِدِّيقًا وَإِيَّاكُمْ وَالْكَذِبَ فَإِنَّ الْكَذِبَ يَهْدِي إِلَى الْفُجُورِ وَإِنَّ الْفُجُورَ يَهْدِي إِلَى النَّارِ وَمَا يَزَالُ الرَّجُلُ يَكْذِبُ وَيَتَحَرَّى الْكَذِبَ حَتَّى يُكْتَبَ عِنْدَ اللَّهِ كَذَّابًا ‏"‏ ‏.‏
Reference : Sahih Muslim 2607c
In-book reference : Book 45, Hadith 136
USC-MSA web (English) reference : Book 32, Hadith 6309
  (deprecated numbering scheme)