What is the ruling on one who committed a prohibited act during Ihram, being ignorant of the expiation (kaffarah) required of them?

Ignorance of the rulings of the rituals leads many pilgrims (Hajj and Umrah performers) into prohibitions. Therefore, whoever intends to perform the rituals must learn their rulings before embarking on them, as seeking knowledge is an obligation upon every Muslim. This means that a Muslim should learn what they need concerning ablution, prayer, zakat, Hajj, and other matters. If a pilgrim in ihram commits one of the prohibited acts out of ignorance of its prohibition, there is nothing upon him, for Allah Almighty says: "And there is no blame upon you for that in which you have erred, but [blame is only] for what your hearts intended." (33:5). However, if one knows that an act is forbidden but did not anticipate all these rulings to apply to it, this is not an excuse, because he knows that the act is forbidden. For example, if a man had intercourse during Ramadan daylight, and was ignorant of what was required of him, the Prophet, peace and blessings be upon him, obligated him to pay expiation.