tiān jī bù kě xiè lòu
lit. mysteries of heaven must not be revealed (idiom); must not be revealed
I am not at liberty to inform you.
天
tiān
day
机
jī
(bound form) machine; mechanism
不
bù
no; not so
可
kě
(prefix) can; may; able to; -able
泄
xiè
(bound form) to leak out; to discharge; (fig.) to divulge
漏
lòu
to leak