Sunan an-Nasa'i, Book 26, Hadith 82 (In-Book) ⓘ
It was narrated that 'Abdullah said: "The Messenger of Allah taught us the Tashahhud for Salah and the Tashahhud upon Al-Hajah. He said: 'The Tashahhud upon the occasion of marriage is: Alhamdu lillahi nasta'inahu wa nastaghfiruhu, wa na'udhu billahi min shururi anfusina, man yahdih Illahu fala mudilla lahu wa man yudlil Illahu fala hadiya lahu, wa ashhadu an la ilaha illallah, wa ashhadu anna Muhammadan 'abduhu wa rasuluhu (Praise be to Allah, we seek His help and His forgiveness. We seek refuge with Allah from the evil of our own souls. Whomsoever Allah guides will never be led astray, and whomsoever Allah leaves astray, no one can guide. I bear witness that there is none worthy of worship but Allah, and I bear witness that Muhammad is His slave and Messenger).' Then he recited three Verses."
أَخْبَرَنَا قُتَيْبَةُ، قَالَ حَدَّثَنَا عَبْثَرٌ، عَنِ الأَعْمَشِ، عَنْ أَبِي إِسْحَاقَ، عَنْ أَبِي الأَحْوَصِ، عَنْ عَبْدِ اللَّهِ، قَالَ عَلَّمَنَا رَسُولُ اللَّهِ صلى الله عليه وسلم التَّشَهُّدَ فِي الصَّلاَةِ وَالتَّشَهُّدَ فِي الْحَاجَةِ قَالَ التَّشَهُّدُ فِي الْحَاجَةِ " أَنِ الْحَمْدُ لِلَّهِ نَسْتَعِينُهُ وَنَسْتَغْفِرُهُ وَنَعُوذُ بِاللَّهِ مِنْ شُرُورِ أَنْفُسِنَا مَنْ يَهْدِهِ اللَّهُ فَلاَ مُضِلَّ لَهُ وَمَنْ يُضْلِلِ اللَّهُ فَلاَ هَادِيَ لَهُ وَأَشْهَدُ أَنْ لاَ إِلَهَ إِلاَّ اللَّهُ وَأَشْهَدُ أَنَّ مُحَمَّدًا عَبْدُهُ وَرَسُولُهُ " . وَيَقْرَأُ ثَلاَثَ آيَاتٍ .
also referenced under: Hadith 3277 (Reference) & Volume 4, Book 26, Hadith 3279 (DarusSalam)