Bhagwad Gita
Chapter 18, Verse 49
असक्तबुद्धिः सर्वत्र जितात्मा विगतस्पृहः।नैष्कर्म्यसिद्धिं परमां संन्यासेनाधिगच्छति।।18.49।।
One can obtain the results of renunciation simply by self-control and by becoming unattached to material things and disregarding material enjoyments. That is the highest perfectional stage of renunciation.