Continuous remembrance can replace supererogatory deeds, whether they be physical, monetary or both such as a supererogatory pilgrimage. This is clear from a hadith which Abu Hurayra transmitted. The poorest of the Emigrants [to Medina] came to the Messenger of God (peace be upon him) and said, 'O Messenger of God, the wealthy have taken the highest degrees and eternal happiness. They pray as we do and fast as we do, but they also have the advantage of wealth, which they use to go on the greater and the lesser pilgrimages and to combat.' The Messenger said, 'Shall I teach you something by which you can catch up with those who have surpassed you and surpass those who are behind you, something in which no one can better you, unless he does as you do?'

'By all means, Messenger!'

'You glorify, praise and magnify [God] after every Prayer,' he said.

It is agreed that this hadith is sound.

For them he replaced with remembrance the hajj, umra, and combat that they were unable to do and told them they could surpass all these through remembrance. The wealthy heard about it, and began the practice in their turn, adding it to the charity and devotional practices [they could perform] with their wealth, thereby achieving two sorts of excellence. The Emigrants who vied with them told the Messenger of God that they now shared this [practice] with them and so had [again] been set apart by something they, the poor, could not do.

'That is the grace of God,' the Prophet replied. 'He gives it to whomever He wills.'

Compiled From:
"The Invocation of God" - Ibn Qayyim al-Jawziyya, pp. 97, 98