Question Summary:
In which order should we recite the Quran in salaat?

Question Detail:

My question is regarding the order in which the quran should be recited in a prayer.
Should we read the surahs or ayahs in the order that they are presented in the quran or cn we recite one surah and then go to another and then come back to that?

Answer :

In the Name of Allah, the Most Gracious, the Most Merciful.
As-salāmu ‘alaykum wa-rahmatullāhi wa-barakātuh.
One should recite the Quran according to the sequence of the Quran in salaat. It is makrooh to deliberately recite the Quran against its sequential order during salaat.[1] It is also makrooh to leave one surah and then proceed to the one after that with the condition that the left out surah is smaller than the one before it which was recited. So for example, if one recites surah al-Kawthar, and then reads surah al-Nasr, it will not be makrooh as, surah al-Kaafiroon, which is after surah al-Nasr, is bigger than surah al-Kawthar.[2] It will, however, be makrooh in the case where one reads, for example, surah Lahab, and then reads surah al-Falaq as surah al-Ikhlaas is smaller than surah Lahab and was missed out.
And Allah Ta’āla Knows Best
Muhammad Haris Siddiqui
Student Darul Iftaa
Melbourne, Australia 
Checked and Approved by,
Mufti Ebrahim Desai.