Second rakaat being shorter than the first rakaat

Q:

1. Must the surah recited in the second rakaat be shorter than the surah recited in the first rakaat?

2. If so, how is the length of a surah determined?

A:

1. Yes.

2. With the number of letters.

And Allah Ta'ala (الله تعالى) knows best.

Answered by:

Mufti Ebrahim Salejee (Isipingo Beach)