Is atonement obligatory upon one who is ignorant (Jahil) or forgetful (Nasi) regarding a prohibited act?
Chapter on Menstruation
Al-Mughni
Book of Purification
Primary text
There are two established legal positions regarding the obligation of atonement for ignorance or forgetfulness. One position asserts that atonement is obligatory based on the general nature of the report (evidence) indicating liability. This is analogized to the expiation required for sexual intercourse during fasting or during Ihram, as it is an expiation incurred due to the act itself.
Supporting text
The opposing view maintains that atonement is not obligatory, supported by the statement of the Prophet, peace be upon him, that his Ummah is pardoned for error and forgetfulness. Furthermore, since expiation aims to remove sin, it is not incumbent upon one who forgot, similar to the expiation for breaking an oath. Under this second view, if a person engages in intercourse with someone who is pure, and she begins menstruating during the act, no expiation is required.