3 times
[ (يَنْفُثُ عَنْ يَسَارِهِ (ثلاثاً)) - (يَسْتَعِيذُ بِاللَّهِ مِنَ الشَّيطَانِ وَمِنْ شَرِّ مَا رَأَى (ثَلاَثَ مَرَّاتٍ)) - ((لاَ يُحَدِّثْ بِهَا أَحَداً)) - ((يَــتَحَوَّلُ عَنْ جَنْبِهِ الَّذِي كَانَ عَلَيْهِ)) ]
Meaning
[((Spit on your left three times)(Spit: A form of spitting comprising mainly of air with little spittle)) - (Seek refuge in Allah from shaytan and the evil of what you saw (Three Times)) - (Do not relate it to anyone) - (Turn and sleep on the opposite side to which you were sleeping on previously.) - (Get up and pray if you so desire.) ]
Source and references
Hisn al-Muslim, entry 114.The reference is copied from the edition; separate editorial verification is not complete yet.
Source edition: Fortress of the Muslim. Open source ↗