Hadith 41

Bulugh al-Maram

Book 2: The Book of Prayer
وَلِأَبِي دَاوُدَ: { لَوَى عُنُقَهُ, لَمَّا بَلَغَ يَمِينًا وَشِمَالاً وَلَمْ يَسْتَدِرْ } 1‏ .‏
"حَيَّ عَلَى اَلصَّلَاةِ "
And also a narration of Abu Dawud - 'he turned his neck to the right and left when he reached Haiya 'alas-Salah (Come to the prayer) and did not turn his body'.