يَمْحُو اللّهُ مَا يَشَاء
Allah blots out what He wills,
of the divinely revealed Books,
وَيُثْبِتُ
and confirms,
until the Qur'an, revealed from Allah to His Messenger peace be upon him, abrogated them all.
Mujahid commented;
يَمْحُو اللّهُ مَا يَشَاء وَيُثْبِتُ
(Allah blots out what He wills and confirms (what He wills).
"Except life and death, misery and happiness (i.e., faith and disbelief), for they do not change."
Mansur said that he asked Mujahid,
"Some of us say in their supplication, `O Allah! If my name is with those who are happy (believers), affirm my name among them, and if my name is among the miserable ones (disbelievers), remove it from among them and place it among the happy ones."
Mujahid said. "This supplication is good."
I met him a year or more later and repeated the same question to him and he recited these Ayat,
إِنَّأ أَنزَلْنَـهُ فِى لَيْلَةٍ مُّبَـرَكَةٍ
We sent it (this Qur'an) down on a blessed night. (44;3)
Mujahid commented next,
"During Laylatul-Qadr (Night of the Decrees), Allah decides what provisions and disasters will occur in the next year of. He then brings forward or back (or blots out) whatever He wills.
As for the Book containing the records of the happy (believers) and the miserable (disbelievers), it does not change."
Al-A`mash narrated that Abu Wa'il, Shaqiq bin Salamah said that he used to recite this supplication often,
"O Allah, if You wrote us among the wretched ones, remove this status from us and write us among the blessed ones. If You wrote us among the blessed ones, please let us stay that way, for surely, You blot out and confirm what You will, and with You is the Mother of the Book."
Ibn Jarir At-Tabari collected this.
Similar statements were collected from Umar bin Al-Khattab and Abdullah bin Mas`ud, indicating that Allah blots out (or abrogates) and affirms what He wills in the Book of Records.
What further supports this meaning is that Imam Ahmad recorded that Thawban said that the Messenger of Allah said,
إِنَّ الرَّجُلَ لَيُحْرَمُ الرِّزْقَ بِالذَّنْبِ يُصِيبُهُ وَلَا يَرُدُّ الْقَدَرَ إِلاَّ الدُّعَاءُ وَلَا يَزِيدُ فِي الْعُمْرِ إِلاَّ الْبِر
A man might be deprived of a provision (that was written for him) because of a sin that he commits; only supplication changes Al-Qadar (Predestination); and only Birr (righteousness) can increase the life span."
An-Nasa'i and Ibn Majah collected this Hadith.
There is also a Hadith recorded in the Sahih that affirms that;
maintaining the ties of the womb increases the life span.
يَمْحُو اللّهُ مَا يَشَاء وَيُثْبِتُ وَعِندَهُ أُمُّ الْكِتَابِ
Allah blots out what He wills and confirms (what He wills). And with Him is the Mother of the Book.
Al-Awfi reported that Ibn Abbas said about Allah's statement,
"A man might work in Allah's obedience for a while but he reverts to the disobedience of Him and then dies while misguided.
This is what Allah blots out, while what He confirms is a man who works in His disobedience, but since goodness was destined for him, he dies after reverting to the obedience of Allah.
This is what Allah confirms."
It was also reported that Sa`id bin Jubayr said that this Ayah is in the meaning of another Ayah,
فَيَغْفِرُ لِمَن يَشَأءُ وَيُعَذِّبُ مَن يَشَأءُ وَاللَّهُ عَلَى كُلِّ شَيْءٍ قَدِيرٌ
Then He forgives whom He wills and punishes whom He wills. And Allah is able to do all things. (2;284