Abu Qilabah said: Malik b. al-Huwairith saw that the prophet (may peace by upon him) would not stand at the end of the first or the third rak’ah until he sat down straight.
The Prophet Muhammad (peace be upon him) was an example for us in all aspects of life including how we pray; therefore it is important for us to follow his example when performing salat so as to gain maximum benefit from it both spiritually and physically. We must remember that prayer is a form of worship which requires concentration and focus on Allah's words; thus taking time between each rak’ahs helps us stay focused on what we are doing instead of rushing through it without paying attention or getting distracted by other thoughts or activities around us.