But those who believe and do deeds of righteousness, We shall soon admit to Gardens, with rivers flowing beneath,- their eternal home: Therein shall they have companions pure and holy: We shall admit them to shades, cool and ever deepening.
Yusuf Ali writes,
The Garden is contrasted with the Fire: the shade
is contrasted with the roasting, Evil grows with what it
So goodness and felicity grow with their practice. The
good may be alone to start with, but (unlike evil ones)
they get Holy Companions.
Just as agony increases with what it suffers (typified by
fresh skins growing as the old ones burns out), so felicity
finds deeper and deeper meaning (typified by the shades
in a garden, which grow deeper and cooler as you
proceed into the interior).
Yusuf Ali, Abdullah. Translation and Commentary of the Quran. Microsoft Word – 004 Nisa’.doc (quran4u.com)