Rituparna tells Nala that he knows the science of gambling and he will teach it to Nala, but that it has to be done by whispering it in his ear because it's a deep and extreme secret.

睿都巴若那对那勒说,他了解赌博术,并且会传授给那勒,但只能是口耳相传,因为这是一个秘密

耶鲁公开课 - 金融市场课程节选