The Ruling on repeating the same Surah and the Ruling on lengthening one Pillar of the Prayer but not the Others

Question :

What is the ruling on repeating the same Surah in the prayer? And what is the ruling on lengthening the prostration more than the bowing? And what is the ruling on making one Rak'ah longer than the others?

Answer:

There is no objection to repeating the same Surah within the Rak'ah but it contradicts what is more fitting; it is better to recite another Surah, whether it be within the same Rak'ah or in two Rak'ahs. What is customary from the time of the Prophet until now is to recite one Surah in the Rak'ah or a number of Verses, then in the following Rak'ah, another Surah or Verses; but there is no objection to repeating them, based upon the generality of Allah's Words:

So recite you of the Qur'an as much as may be easy for you.

As for the bowing and the prostration, it is permissible to prolong them for the individual worshipper according to his zeal, even if it be very much. But as for the Imam, the least perfect thing is for him to say: "Subhana Rabbial-A'la"

(Glorified be my Lord, the Most High) three times and the most perfect thing is for him to say it ten times. The one praying behind the Imam should glorify Allah for as long as the Imam remains bowing or prostrating. It is permissible to make some of the Rak'ahs longer than others, but the Sunnah is for the first Rak'ah to be longer than the second in recitation; and in the bowing and the prostrations, the pillars of the prayer should be of similar length.

Source:
Ibn Jibreen
Fatawa Islamiyah, Vol. 2 Pages 235-236