Shaykh ‘Abdu-Razzāq al-Badr:

It is recommended for a fasting person to frequently remember Allah while fasting so as to excel in his fasting.

In a Ḥadīth which some scholars deem authentic, the Prophet ﷺ was asked about a number of religious observances; among which was fasting. It was said to him: Which fasting person attains the most reward? He ﷺ replied: “Those who engage in the remembrance of Allah the most”.

Imām Ibn al-Qayyim, in his book al-Wābil-us-Sayyib, derived a beneficial principle from this Ḥadīth that pertains to all acts of worship: The person who attains the most reward in any form of worship is he who engages in the remembrance of Allah the most while in that worship.