stealthy

marked by quiet and caution and secrecy; taking pains to avoid being observed; "a furtive manner"; "a sneak attack"; "stealthy footsteps"; "a surreptitious glance at his watch"

वह दीवारों को दबा दबाकर मजबूत करती है.

Or do they think We do not hear their secrecies and stealthy consultations? In fact, Our messengers who attend them record everything.