Question:
Assalamou alaykoum Shaykh
We join the fard prayers after it started, lets say at the second rakaates, when the Imam gives salam we stand up to complete what we are missing. Do I read the thanaa before Alhamdolillah? Now there is a rule to read from bigger to smaller verses so does that rule apply if we don’t know what number of surah the Iman has recited to recite one which is a smaller surah?
Answer:
When you join the fard prayer after it started, for example at the second raka`at, to you it is still your first raka`at, so you follow the normal etiquette of making your reading slightly longer than in the following one. You need only start with A`udhu billah... without the entire opening du`a.
Hajj Gibril Haddad