Imam Shafi’i (may Allah have mercy on him) says that whoever, seeking closeness to Allah, makes a vow without taking an oath that he will perform i’tikaf standing, will not speak to anyone, will not eat food, and will not lie on a bed, then he may sit without giving expiation, may speak, may eat food, and may rest on the bed. Indeed, only that vow should be fulfilled in which there is obedience and submission to Allah Almighty. As for the person who made such a vow in which there is no obedience to Allah, then he should neither fulfill the vow nor give expiation.“It is narrated from Sayyidah Aisha (may Allah be pleased with her) that the Messenger of Allah (peace and blessings be upon him) said: ‘Whoever made a vow to obey Allah, let him obey Him, and whoever made a vow to disobey Allah, let him not disobey Him.’”

Imam Abu Bakr (may Allah have mercy on him) says that in the narration of Sayyiduna Ibn Abbas (may Allah be pleased with them both), the Prophet Muhammad (peace and blessings be upon him) saw Abu Isra’il standing in the sun and asked:“What has happened to him that he is standing in the sun?”The companions replied that he had made a vow to fast, not to sit, and not to seek shade. The Prophet (peace and blessings be upon him) said:“Tell him to sit down, stay in the shade, and complete his fast.”Thus, the Messenger of Allah (peace and blessings be upon him) ordered him to fulfill the vow of fasting because fasting is obedience and servitude to Allah, and forbade him from standing in the sun because standing in the sun is not an act of obedience and servitude to Allah. Although standing in the sun is not a sin, if it causes physical harm, then it becomes sinful. I have explained this matter in detail in the Book of Vows.