Narrated Abdullah ibn Abbas: Ma'iz ibn Malik came to the Prophet (ﷺ) and admitted fornication twice. But he drove him away. He then came and admitted fornication twice. But he drove him away. He then came and admitted fornication twice. He (the Prophet) said: You have testified to yourself four times. Take him away and stone him to death.
Source: sunnah.com
Other translations
Arabic
حَدَّثَنَا نَصْرُ بْنُ عَلِيٍّ، أَخْبَرَنَا أَبُو أَحْمَدَ، أَخْبَرَنَا إِسْرَائِيلُ، عَنْ سِمَاكِ بْنِ حَرْبٍ، عَنْ سَعِيدِ بْنِ جُبَيْرٍ، عَنِ ابْنِ عَبَّاسٍ، قَالَ جَاءَ مَاعِزُ بْنُ مَالِكٍ إِلَى النَّبِيِّ صلى الله عليه وسلم فَاعْتَرَفَ بِالزِّنَا مَرَّتَيْنِ فَطَرَدَهُ ثُمَّ جَاءَ فَاعْتَرَفَ بِالزِّنَا مَرَّتَيْنِ فَقَالَ " شَهِدْتَ عَلَى نَفْسِكَ أَرْبَعَ مَرَّاتٍ اذْهَبُوا بِهِ فَارْجُمُوهُ " .
sunnah.com