Hadrat Maulānā Muhammad Qamar az-Zamān Sāhib Allāhābādī dāmat barakātuhum.
My dear friends! The outward fast entails keeping away from food, drink and one’s wife for a few hours. However, the real fast is to remove everything apart from Allāh ta‛ālā in such a manner that we do not even turn our attention towards it. We should not merely abstain from food and drink. Rather, we should abstain from everything apart from Allāh ta‛ālā.
Real abstention means abstaining from everything apart from Allāh ta‛ālā. Abstention from food and drink are signs of outward fasting. Internal fasting means that anything apart from Allāh ta‛ālā must not be able to enter the sanctuary of the heart. This is the real fast.
My dear friends! We should not confine ourselves to mere abstention from food and drink. Instead, we must do as much as we can externally, e.g. evil glances may be cast with the eyes (so we must do our utmost to save ourselves from it), evil thoughts may enter the heart. We must safeguard our hearts against all this. This is the fast in the true meaning of the word. May Allāh ta‛ālā inspire us all.
Mawā‛iz al-Ihsān, vol. 1, p. 45.