Tuma'neenah is a pillar of the prayer
27-5-2012 | IslamWeb
Question:
Asalaamu Alaikum, How fast should one make their salat? There are brothers at the mosque who pray 4 rakat in 2-3 minutes, maximum 5 minutes, very quickly, and these are brothers who are known to be knowledgeable about matters of Islam and known to be pious. Then there are some brothers who may take 10 minutes to pray 4 rakat. These brothers always feel pressured to pray quickly when in the Masjid and such because everyone around them is praying so quickly. If they reach the Masjid 5 minutes before Dhuhr salat, for example, they don't pray 4 sunnah because they know jamaat will start when they are in the middle of making their sunnah. Yet, other brothers seem to come 2-3 minutes before jamaat time and make their 4 sunnahs very quickly. What is the ruling on this?
Answer:
All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.
It is not possible to determine the minimum time in minutes during which the prayer could be performed. What is important is that it should be performed with Tuma’neenah (tranquility in each position of the prayer) because Tuma’neenah is one of the pillars of the prayer without which the prayer is void as we clarified in Fatwa 90057.
The scholars 
defined the Tuma’neenah as a praying person’s limbs remaining motionless because this is being motionless between two movements (i.e. positions of the prayer). The Hanbali Scholars said: “The minimum of it (Tuma’neenah) is that one observes tranquility even if this is for a short period.” Al-Mardaawi 
said: “This is the correct view of the (Hanbali) School, and it was also said ‘It is to the extent of being able to say the obligatory mention of Allaah [in a particular position of the prayer].”
Therefore, if someone performs the prayer while observing the Tuma’neenah, then his prayer is valid even if he had performed it in only two or three minutes, and if one prayed while not observing the Tuma’neenah, then his prayer is invalid even if he had performed it in more than that period of time.
On the other hand, it is enough and acceptable to pray the Raatibah (i.e. the supererogatory prayer that is performed either before or after the obligatory prayer) before the Thuhr prayer only two Rak’ahs. Therefore, if someone comes to the mosque while not having enough time to pray four Rak'ahs before the Iqaamah (the call that is made immediately prior to commencing the prayer), then he may pray two Rak’ahs only.
Allaah Knows best.