“He does not perfect the prayer ..."

Umar said, while standing on the podium:

“A man might have white hair in Islam, yet has not completed even one prayer for Allah, the Exalted!” He was asked, “Why is that?” He said, “He does not perfect the prayer’s required Khushu`, solemness and attending to Allah with his heart.”

["Al-Ihyaa", 10/202].