The Book of Virtue, Enjoining Good Manners, and Joining of the Ties of Kinship
Ṣaḥīḥ Muslim 6639
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
ʿalaykum bi-aṣ-ṣidqi fa-inna aṣ-ṣidqa yahdī ilā al-birri wa-inna al-birra yahdī ilā al-jannah wamā yazālu ar-rajulu yaṣduqu wayataḥarrā aṣ-ṣidqa ḥattā yuktaba ʿinda-Llāh ṣiddīqan wa-iyyākum wa-l-kadhiba fa-inna al-kadhiba yahdī ilā al-fujūri wa-inna al-fujūra yahdī ilā an-nāri wamā yazālu ar-rajulu yakdhibu wayataḥarrā al-kadhiba ḥattā yuktaba ʿinda-Llāh kadhāban
Transliteration generated from the Arabic vowel marks
The full narration
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
Source
Ṣaḥīḥ Muslim · 6639