Tafsir of Fatir 35:11

If you ask: "A human is either mu‘ammar (long-lived) or manqus (short-lived). It is impossible for both long life and its opposite to occur to the same person, so how is it valid to say: {And no aged person is granted a long life, nor is his life lessened}?"

I say: This is among the speech that is treated with leniency, relying on the understanding of the listeners and trusting their ability to grasp the meaning through their intellects, as it is not confusing to them that a single life cannot be both long and short simultaneously. This is common in the speech of people; they say: "Allah does not reward a servant nor punish him except with justice," and "I have not enjoyed a land nor found it disagreeable except that my reward in it was little."

There is another interpretation: It means that no human’s life is lengthened or shortened except that it is in a Book. The form of this is that it is written on the Preserved Tablet: "If so-and-so performs Hajj or goes on a military expedition, his life is forty years; and if he performs both, his life is sixty years." If he combines them and reaches sixty, he has been granted a long life. If he performs only one and does not exceed forty, then his life has been lessened from the ultimate limit, which is sixty.

The Messenger of Allah (peace be upon him) alluded to this in his saying: "Charity and maintaining family ties lengthen homes and increase lifespans."

When Umar (may Allah be pleased with him) was stabbed, Ka‘b said: "If Umar had prayed to Allah, He would have delayed his term." It was said to Ka‘b: "Has Allah not said: {When their term comes, they cannot delay it an hour nor advance it} (Yunus: 49)?" He replied: "But Allah has also said: {And no aged person is granted a long life}." It is widespread on tongues to say: "May Allah lengthen your remaining time," and "May He extend your duration," and the like.

Sa‘id ibn Jubayr (may Allah be pleased with him) said: "His life is written in the scroll as such-and-such years, then at the bottom of it is written: 'A day has passed, two days have passed,' until it reaches its end."

Qatadah (may Allah be pleased with him) said: "The mu‘ammar is one who reaches sixty years, and the manqus (shortened) in his life is one who dies before sixty years." The "Book" is the Tablet.

Ibn Abbas (may Allah be pleased with them both) said: It is permissible that "the Book of Allah" refers to the knowledge of Allah, or the scroll of the human.

It was recited: {wa-la yanquṣu} (nor does he lessen) in the active voice, from ‘amara (to lengthen), with the lightened form.