If you have a bad dream in your sleep, you should spit three times on the left side, then say three times -
أَعُوْذُ بِاللَّهِ مِنَ الشَّيْطَانِ الرَّجِيمِ
Pronunciation
A'oodhu billaahi minash-Shaytaanir-rajeem
Meaning
I seek refuge in Allah from Satan the outcast. One need to change sides in their sleep. It is forbidden to tell this dream in front of anyone. Even if you have good dreams, you don't have to tell anyone. But it can be said in front of a close friend or in front of wise people. Narrated Abu Qatadah (RA): The Prophet (ﷺ) said: A good dream is from Allah. And bad dreams are from the devil. So whoever has a good dream, let him reveal it to the one he loves. And if anyone has a bad dream, let him seek refuge in Allah from its harm and from the evil of Satan, and spit three times to the left. Don't reveal the dream to anyone. Then it will not be able to harm him. [1] Jarir (RA) said, Rasulullah (ﷺ) said, when one of you has a dream that he dislikes, he should spit three times to his left. And he seeks refuge in Allah from Satan three times and changes sides. [2] Abu Hurairah (RA) said: The Messenger of Allah (ﷺ) said: If a person has a bad dream, he should get up and pray two rak'ahs. [3]
Source: [1] Bukhari: 7044 [2] Muslim: 6041 [3] Sahih (Albani). Tirmidhi: 2280
Read the hadith
حَدَّثَنَا سَعِيدُ بْنُ الرَّبِيعِ، حَدَّثَنَا شُعْبَةُ، عَنْ عَبْدِ رَبِّهِ بْنِ سَعِيدٍ، قَالَ سَمِعْتُ أَبَا سَلَمَةَ، يَقُولُ لَقَدْ كُنْتُ أَرَى الرُّؤْيَا فَتُمْرِضُنِي حَتَّى سَمِعْتُ أَبَا قَتَادَةَ يَقُولُ وَأَنَا كُنْتُ لأَرَى الرُّؤْيَا تُمْرِضُنِي، حَتَّى سَمِعْتُ النَّبِيَّ صلى الله عليه وسلم يَقُولُ " الرُّؤْيَا الْحَسَنَةُ مِنَ اللَّهِ، فَإِذَا رَأَى أَحَدُكُمْ مَا يُحِبُّ فَلاَ يُحَدِّثْ بِهِ إِلاَّ مَنْ يُحِبُّ، وَإِذَا رَأَى مَا يَكْرَهُ فَلْيَتَعَوَّذْ بِاللَّهِ مِنْ شَرِّهَا، وَمِنْ شَرِّ الشَّيْطَانِ وَلْيَتْفِلْ ثَلاَثًا وَلاَ يُحَدِّثْ بِهَا أَحَدًا فَإِنَّهَا لَنْ تَضُرَّهُ " .
Narrated Abu Salama: I used to see a dream which would make me sick till I heard Abu Qatada saying, "I too, used to see a dream which would make me sick till I heard the Prophet (ﷺ) saying, "A good dream is from Allah, so if anyone of you saw a dream which he liked, he should not tell it to anybody except to the one whom he loves, and if he saw a dream which he disliked, then he should seek refuge with Allah from its evil and from the evil of Satan, and spit three times (on his left) and should not tell it to anybody, for it will not harm him. " [[1] Bukhari: 7044 [2] Muslim: 6041 [3] Sahih (Albani). Tirmidhi: 2280]
Duas from IslamicAPI's Masnun Dua dataset (based on the Quran, hadith, Hisnul Muslim and Rahe Belayat). See the dataset