كتاب الصلاة
2  
The Book of Prayer
Bulugh al-Maram 235
In another narration:
"for there is a Satan with him."
وَفِي رِوَايَةٍ : { فَإِنَّ مَعَهُ اَلْقَرِينَ } 1‏ .‏
Reference : Bulugh al-Maram 235
In-book reference : Book 2, Hadith 235
English translation : Book 2, Hadith 233
Hadith Text
Reference