My father narrated to us. He said: Al-Hasan b. Ahmad al-Maliki narrated to us. He said: Mansur b. al-`Abbas narrated to us from Muhammad b. Abi `Umayr from Hisham b. Salim from Zayd al-Shahham from Abi `Abdillah al-Sadiq . He said:

Whoever recites qul huwallahu ahad sixty times in the first two units of the night prayer (salat al-layl) – thirty times in each unit – he will be left with no sins between him and Allah.