Tafsir of Al-Teen 95:6

إﻻ الذين آمنوا وعملوا الصالحات

Save those who believe and do righteous deeds. Some have said,

ثم رددنه أسفل سفلين

(Then We reduced him to the lowest of the low). "This means decrepit old age.'' This has been reported from Ibn `Abbas and `Ikrimah. Ikrimah even said, "Whoever gathers the Qur'an (i.e., he memorizes it all), then he will not be returned to decrepit old age.'' Ibn Jarir preferred this explanation. Even if this was the meaning, it would not be correct to exclude the believers from this, because some of them are also overcome by the senility of old age. Thus, the meaning here is what we have already mentioned (i.e., the first view), which is similar to Allah's saying,

والعصر إن اﻻنسن لفى خسر إﻻ الذين ءامنوا وعملوا الصلحت

By Al-`Asr. Verily man is in loss, except those who believe and perform righteous deeds. (103:1-3) Concerning Allah's statement,

فلهم أجر غير ممنون

Then they shall have a reward without end. meaning, that will not end, as we have mentioned previously. Then Allah says,