the virtues found in salah with khushu'

WHAT IS KHUSHU? 

Meaning: 

Calmness, serenity, tranquility, dignity and humility.

One gains khushu from a fear of Allah and the sense that He is always watching. It means that one’s heart stands before its Lord with humility and submission. Allah tells us:

“…and stand before Allah with obedience.” 

 (Surah al-Baqarah 2:238)

Khushu in the prayer happens when a person empties their heart for prayer, and focuses on it to the exclusion of all else, and prefers it to everything else. Only then do they find comfort and joy in it as the Prophet, SallAllahu Alayhi Wa Sallam, said,

“…and my joy has been made Salah.” 

(Recorded in Ahmad)