Bhagavad Gita 7.11
बलं बलवतां इच्छां कामरागविवर्जितम् |
धर्मविरुद्धो भूतेषु कामोऽस्मि भरतर्षभ
Translation
O best of the Bharatas, in strong persons, I am their strength devoid of desire and passion. I am sexual activity not conflicting with virtue or scriptural injunctions.