Ali reciting the "Ayat (verse) of light" from the "Surat (chapter) of light" from the Holy Quran.

Allah is the Light of the heavens and the earth.
The parable of His Light is a niche wherein is a lamp—
the lamp is in a glass, the glass as it were a glittering star—
lit from a blessed olive tree,
neither eastern nor western,
whose oil almost lights up,
though fire should not touch it.
Light upon light.
Allah guides to His Light whomever He wishes.
Allah draws parables for mankind,
and Allah has knowledge of all things.

Translation by Ali Quli Qara'i