What is meant by abrogated verses, how are they known, what is the difference between them and other verses, and is it obligatory for a Muslim to know them?

Abrogation (Naskh) is the annulment of a legal ruling by a later, distinct legal address. Abrogated verses fall into three categories:

1. Abrogation of its ruling while its recitation remains: Such as the abrogation of the ruling regarding the waiting period (iddah) for a widow, changing it from a full year to four months and ten days. 2. Abrogation of both its ruling and its recitation: As in the abrogation of the number of sucklings that establish prohibition (mahramiyyah) from ten to five. 3. Abrogation of its recitation while its ruling remains: Such as the abrogation of the recitation of the verse of stoning for the married fornicator.

The difference between the abrogated and the non-abrogated is that the abrogated is not acted upon after the revelation of the abrogating text (in the first two categories), and it is not recited for worship (in the third category). In contrast, the non-abrogated is acted upon and its recitation is an act of worship. One can learn about abrogated verses from books such as "Al-Nasikh wa Al-Mansukh" by Al-Nahhas and Ibn Al-Arabi, and books of interpretation (tafsir) based on narrations (ma'thur). Learning about the abrogating and abrogated texts is obligatory for anyone who undertakes teaching people and issuing fatwas, in order to avoid issuing rulings based on abrogated evidence.