Dua against distractions and whispering of shaitan

Invocation against the distractions of Satan during the prayer and recitation of the Qur'an
 

أَعُوذُ بِاللَّهِ مِنَ الشَّيْطانِ الرَّجِيْمِ

138. 'A'oothu billaahi minash-Shaytaanir-rajeem.

I seek refuge in Allah from Satan the outcast (then spit to your left). (Do this three times reciting in Arabic.)

Reference: Muslim 4/1729