تفسير : (and allah knoweth best what they are hiding) and allah knows best what they say and do; and it is also said this means: allah knows best what they hear and hide in their hearts.
Jalāl al-Dīn al-Maḥallī
تفسير : and god knows best what they are amassing, accumulating in their scrolls, in the way of disbelief, denial and evil deeds.