Reference : Hisn al-Muslim 114

يَنْفُثُ عَنْ يَسَارِهِ (ثلاثاً).
يَسْتَعِيذُ بِاللَّهِ مِنَ الشَّيطَانِ وَمِنْ شَرِّ مَا رَأَى (ثَلاَثَ مَرَّاتٍ).
لاَ يُحَدِّثْ بِهَا أَحَداً.
يَــتَحَوَّلُ عَنْ جَنْبِهِ الَّذِي كَانَ عَلَيْهِ.
Spit to your left (three times).1

Seek refuge in Allah from the Devil and from the evil of what you have seen 
(three times).2

Do not speak about it to anyone.3

Turn over on your other side.4


Reference:
1. Muslim 4/1 772.
2. Muslim 4/1 772, 3.
3. Muslim 4/1772.
4. Muslim 4/1773.

Chapter: Upon seeing a good dream or a bad dream