The 21st verse in Chapter 16 says
'Trividham narakas Yedam dwaaram naashanam aatmanh
kaamah krodhah tatha lobhah tasmad edad tryam tyajet'
The three doors to hell are attachment, greediness and anger. So enjoins upon Arjuna and all of us to do away with these three. In Chapter 2 he says that attachment leads to greediness which in turn to anger ultimately to destruction. Here he forbids all the three factors. The assertion is very emphatic