Bg 7.11

balam balavatam caham
kama-raga-vivarjitam
dharmaviruddho bhutesu
kamo ’smi bharatarsabha

Word for word: 
balam — strength; bala-vatam — of the strong; ca — and; aham — I am; kama — passion; raga — and attachment; vivarjitam — devoid of; dharma-aviruddhah — not against religious principles; bhutesu — in all beings; kamah — sex life; asmi — I am; bharata-rsabha — O lord of the Bharatas.

Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
I am the strength of the strong, devoid of passion and desire. I am sex life which is not contrary to religious principles, O lord of the Bharatas [Arjuna].

Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
The strong man’s strength should be applied to protect the weak, not for personal aggression. Similarly, sex life, according to religious principles (dharma), should be for the propagation of children, not otherwise. The responsibility of parents is then to make their offspring Krishna conscious.