Shaikh Ibn ul-Uthaymeen rahimahullah was asked:
If I was praying alone and I made a mistake in the recitation in a verse and I was unable to complete it and I mixed it up with another verse, what should I do while I am in the prayer?
“It is for you to do one of two things: either you move to another verse after it or either you make ruku’ because the matter in this [issue] is spacious”.
[Nur ‘ala Darb no. 493]
Faisal bin Abdul Qaadir bin Hassan