Qutub e ‘alam Shaykh al-mashaikh Mawlana Rasheed Ahmad Gangohi (Allah have mercy on him) wrote,

‘The remembrance of Allah (dhikr) is such a thing that if done consistently even with (non-volitional) unawareness, random thoughts, stress of worldly involvements merely with the movement of tongue then also it is beneficial and illuminates the qalb (heart).’

Madhmoon e dhikr, Majmua’ Talefat e Muslih al-Ummat ra, volume 3, page 6