The Great Epic of the Bhārata dynasty 1.193.2

1.193.2

atasteṣāṃ guṇāneva kīrtayāmi viśeṣataḥ |
nāvabudhyeta viduro mamābhiprāyamiṅgitaiḥ || 2 ||

"Vaisampayana said, 'Dhritarashtra replied saying, I desire to do exactly what you would recommend. But I do not wish to inform Vidura of it even by a change of muscle. It was, therefore, O son, that I was applauding the Pandavas in Vidura's presence, so that he might not know even by a sign what is in my mind. Now that Vidura hath gone away, this is the time, O Suyodhana (Duryodhana), for telling me what thou hast hit upon, and what, O Radheya (Karna), thou too hast hit upon.'