"We were talking about something, and I had only recently left Jahiliyyah behind, so I swore by Al-Lat and Al-'Uzza. The Companions of the Messenger of Allah said to me: 'What a bad thing you have said! Go to the Messenger of Allah and tell him, for we think that you have committed Kufr.' So I went to him and told him, and he said to me: 'Say: La ilaha illallah wahdahu la sharika lah (There is none worthy of worship except Allah alone, without partner) three times, and seek refuge with Allah from the Shaitan three times, and spit dryly to your left three times, and do not say that again.'" (Using translation from Nasāʾī 3776)  

كُنَّا نَذْكُرُ بَعْضَ الْأَمْرِ وَأَنَا حَدِيثُ عَهْدٍ بِالْجَاهِلِيَّةِ فَحَلَفْتُ بِاللَّاتِ وَالْعُزَّى فَقَالَ لِي أَصْحَابُ رَسُولِ اللهِ ﷺ بِئْسَ مَا قُلْتَ ائْتِ رَسُولَ اللهِ ﷺ فَأَخْبِرْهُ فَإِنَّا لَا نَرَاكَ إِلَّا قَدْ كَفَرْتَ فَلَقِيتُهُ فَأَخْبَرْتُهُ فَقَالَ «قُلْ لَا إِلَهَ إِلَّا اللهُ وَحْدَهُ ثَلَاثَ مَرَّاتٍ وَتَعَوَّذْ مِنَ الشَّيْطَانِ ثَلَاثَ مَرَّاتٍ وَاتْفِلْ عَنْ شِمَالِكَ ثَلَاثَ مَرَّاتٍ وَلَا تَعُدْ لَهُ»  

"I swore by Al-Lat and Al-'Uzza and my companions said to me: 'What a bad thing you have said! You have said something horrible.' So I went to the Messenger of Allah and told him about that. He said: 'Say: La ilaha illallah wahdahu la sharika lah, lahul-mulk wa lahul-hamd wa huwa 'ala kulli shay'in qadir (There is none worthy of worship except Allah with no partner or associate; His is the Dominion, to Him be all praise, and He is able to do all things). Spit to your left three times, seek refuge with Allah from the Shaitan, and do not say that again.'" (Using translation from Nasāʾī 3777)  

أَصْحَابِي بِئْسَ مَا قُلْتَ هُجْرًا فَأَتَيْتُ رَسُولَ اللهِ ﷺ فَذَكَرْتُ ذَلِكَ لَهُ فَقَالَ «قُلْ لَا إِلَهَ إِلَّا اللهُ وَحْدَهُ لَا شَرِيكَ لَهُ لَهُ الْمُلْكُ وَلَهُ الْحَمْدُ وَهُوَ عَلَى كُلِّ شَيْءٍ قَدِيرٌ وَانْفُثْ عَنْ شِمَالِكَ ثَلَاثًا وَتَعَوَّذْ بِاللهِ مِنَ الشَّيْطَانِ الرَّجِيمِ ثُمَّ لَا تَعُدْ»