"Shall I not inform you of the best of your actions, the purest in the sight of your Lord, which raises your rank to the highest, which is better for you than spending gold and silver, better than meeting your enemy so that you strike at their necks and they strike at yours?'
They replied: 'Yes, indeed,' and he said: 'It is the remembrance of Allah." (At-Tirmidhi) Narrated by Abu Darda Ra