One day you will repent-----what you have done

over

for

about

One day you will repent for what you have done

The word 'repent' takes the preposition 'for' after it.

'for' means with the object or purpose of.

It indicates the suiting of purpose for something

'Repeat' means to feel sorrow or regret for what one has done

so we say repeat for something.

ND11-2-2023