Kamasutra 5.6.40

5.6.40

kāmopadhāśuddhān rakṣiṇo 'ntaḥpure sthāpayed ity ācāryāḥ/

For these reasons a man should guard his own wife. Old authors say that a King should select for sentinels in his harem such men as have had their freedom from carnal desires well tested. But such men, though free themselves from carnal desire, by reason of their fear or avarice, may cause other persons to enter the harem, and therefore Gonikaputra says, that Kings should place such men in the harem as may have had their freedom from carnal desires, their fears, and their avarice well tested. Lastly Vatsyayana says that under the influence of Dharma people might be admitted, and therefore men should be selected who are free from carnal desires, fear, avarice, and Dharma.