(loanword) rabbi

lit. to attend to one thing and lose sight of another (idiom); fig. to be unable to manage two or more things at once; cannot pay attention to one thing without neglecting the other

to favour one and discriminate against the other

know yourself, know your enemy (idiom, from Sunzi's "The Art of War" 孫子兵法|孙子兵法[Sun1 zi3 Bing1 fa3])

either this or that; one or the other