It is conditioned by three conditions: 1. That he knows in his heart that he is fasting, so the determination of the heart on what he intends to do in fasting is a condition, or his knowledge in his heart that he is fasting. His intention to wake up for suhoor with the intention of fasting is considered an intention, while verbalizing the intention is recommended but not a condition. As mentioned in Al-Hadiyah Al-‘Alaiyah p. 155, and in Al-Fatawa Al-Hindiyyah 1: 195. 2. That he knows in his heart which fast he is observing, and this is only required for fasting that needs specification, which is every fast other than the fast of Ramadan, a specified vow, and voluntary fasting. 3. To remain steadfast in it: If he retracts from what he intended at night, he does not become a faster, and if he breaks his fast, there is nothing upon him. However, if he returns to renew the intention at its time, his fast is valid.