In which parva and in what context does Vyasa say the following shlokha in the Mahabharata?
You can listen to it here: https://clyp.it/bqm01ao5, I tried transliterating it as below.
yasmin yadAvartitavyO yOmanushyaha tasmin tadAvartitavyam sadharmaha mAyAcharo mAyayAvArarenah sAdhvachArah sAdhunA prathyupeyah
He's supposedly speaking on how to beat adharma with adharma.