A verse and its Tafsir
Allah the Exalted says
“Is he who founded his building upon duty to Allah and His good pleasure better; or he who founded his building on the brink of a crumbling, overhanging precipice so that it toppled with him into the fire of hell? Allah guideth not wrongdoing folk.” (9:109)
Its meaning is
He established a foundation and a base for its structure
It is the base upon which things are built
It is said
As and asas (foundation)
The plural of as is asas
Mufradat al-Qur'an
By al-Raghib al-Isfahani