Assalam o alaikum dear scholars. What is ruling about performing taraweeh very fast in a way that recitation could not be understood/heard clearly. Is this way of performing taraweeh acceptable to Allah. Jazakallah

All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad, sallallaahu ʻalayhi wa sallam, is His Slave and Messenger.

If the speed of the recitation leads to mispronunciation, omitting some letters or substituting some letters with others, the reciter bears a sin for that because he has not recited the Quran properly as it was revealed. However, if he recites the Faatihah chapter properly and no letter or a Shaddah (germination or consonant doubling) is omitted, his prayer is valid.

If the reciter is reading the Quran fast but pronounces and articulates each letter properly according to the rules of proper pronunciation, his recitation is valid; however, his act contradicts that which is better and religiously superior to do. It is better to recite the Quran slowly as it helps the reciter to understand and ponder over its meanings. Allah, The Exalted, says (what means): {... And recite the Quran with measured recitation.} [Quran 73:4]

As for the fast performance of the acts of the prayer that are considered among its pillars such as the Rukoo' (bowing), raising one's head after the Rukoo', the Sujood (prostration), and sitting down between the two prostrations) undermining the Tuma’aneenah (tranquility in each position of the prayer), it renders the prayer invalid. If such fast performance does not undermine the Tuma’aneenah, the prayer is valid. The limit of Tuma’neenah is that each body part settles in its place for the least time possible (before one moves from one position to another). Some scholars estimated it with the time of reciting one Tasbeeh.

Allah Knows best.