Hisn al-Muslim

A`ūdhu billāh (Say:) I seek refuge in Allah. (Then you should desist from doing what you are in doubt about.) Reference: Al-Bukhari, cf. Al-Asqalani, Fathul-Bari 6/336, Muslim 1/120.

يَسْتَعِيذُ بِاللَّهِ.
يَنْتَهِي عَمَّا شك فِيهِ.