What is the best [thing] to read or supplicate with to seek refuge in Allah from the whispers of Satan and disturbing thoughts, especially during prayer?

The best ways to dispel intrusive thoughts and distractions in prayer are:

1. Arriving early and performing ablution perfectly.

2. Performing supererogatory prayers, and occupying oneself with Quran recitation and remembrance (dhikr) before the obligatory prayer.

3. The servant's diligent effort to maintain mental and intellectual presence during recitation and to achieve tranquility in prayer.

4. Seeking refuge with Allah from the accursed Shaytan before reciting Al-Fatiha in the first rak'ah, by saying: "A'udhu Billahi As-Sami' Al-'Alim min Ash-Shaytan Ar-Rajim min hamzihi wa nafkhyhi wa nafthihi" (I seek refuge with Allah, the All-Hearing, the All-Knowing, from the accursed Shaytan, from his evil suggestions, his arrogance, and his poetry/evil whisperings).

5. Supplicating with a submissive heart to repel the Shaytan's whisperings.

6. If intrusive thoughts occur, seek refuge with Allah, then lightly spit to the left three times.