I need to know about Al-Naasikh and Al-Mansookh in the Quran.

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.

An-Naasikh and Al-Mansookh, are two terms among the terms of the principles of Islamic jurisprudence. Naskh means abrogating a religious ruling with a new and recent text, in a way that if the latter text had not been revealed, the former ruling would still be valid and applicable.

It has three pillars:

1-     An-Naasikh is Allaah and His Prophet in things in which Allaah permitted him to change. Therefore, it is not possible for anyone to claim that a religious ruling has been abrogated except with evidence from the Book of Allaah and the Sunnah of the Prophet .

2-     Al-Mansookh 'Anhu is the previous ruling.   

3-     Al-Mansookh Ilayhi is the new ruling;

An example for all this would be as follows:

The fasting of the day of 'Aashooraa' was obligatory at the beginning of Islam, then Allaah abrogated its obligation with the fasting of the month of Ramadan. So An-Naasikh is Allaah, and Al-Mansookh 'Anhu is the obligation of the fasting of 'Aashooraa', and Al-Mansookh Ilayh is the fasting of the month of Ramadan.

Allaah Knows best.