It is Arjuna who worries about varna shankara. Krishna ignores Arjuna's remark. Instead he talks of Varna being based on karma and guna.
According to the aptitudes resulting from the dispositions of Nature
(gunas) and works (karma), the social order of fourfold division has
been created by Me. Though I am their originator, know me to be an
agent but ...
The OP is referring to, perhaps, to the following sloka from the 3rd chapter of BG.
ज्यायसी चेत्कर्मणस्ते मता बुद्धिर्जनार्दन।
तत्किं कर्मणि घोरे मां नियोजयसि केशव।।3.1।।
Arjuna said O Janardana, if knowledge is held to be superior to action
by You, then why do You engage me in action that is terrible, O Kesava
The following slokas are to ...
Kunti exposed this truth to pandavas in Stri parva:26.
That hero and great bowman, that leader of leaders of car-divisions, that warrior distinguished by every mark of heroism, who hath been slain by Arjuna in battle, that warrior whom, ye sons of Pandu, ye took forth, Suta’s child born of Radha, that hero who shone in the midst of his forces like the ...