Ayat 14 of Surat Ta-Ha of the Holy Qur'an (20:14) reads:--
"Verily, I am Allah:
There is no god but I:
So serve Me (only),
And establish regular (sallat)
prayer for celebrating My Praise (Zikr)."
Here, establishing Sallat means having spiritual connection with Allah Ta'ala and observing Him in the heart, as the Prophet, Sallallahu alaihi Wasallam, said: "There is no Sallat without the presence of heart (before Allah)."
In offering Sallat with presence of heart, our organs are busy in bowing and prostrating, the tongue will be reciting the Qur'an but the heart is engrossed in the remembrance and vision of Allah...