(Prabhupada's lecture - Śrīmad-Bhāgavatam 1.16.10 - Los Angeles, January 7, 1974)
That is the instruction by Cāṇakya Paṇḍita, a great politician moralist. He said that "Who is learned scholar?" He was himself very learned scholar, but he is giving definition of learned scholar. What is that? Mātṛvat para-dāreṣu: "Anyone who sees all woman..." Para-dāreṣu. Para-dāra means other's wife. Para-dāreṣu. Mātṛvat. Not his own wife, but other's wife. So except one has got one wife, and all others, other's wife. So mātṛvat para-dāreṣu, to treat and see other's wife as mother. Mātṛvat para-dāreṣu. Para-dravyeṣu loṣṭravat: "And other's property as garbage in the street." As nobody is interested in the garbage on the street, similarly, if one is not interested in anyone's property... It may be insignificant thing, but one cannot touch it. Tena tyaktena bhuñjīthā mā gṛdhaḥ kasya svid dhanam [Īśo mantra 1].
This is the Upaniṣad. Īśopaniṣad, Vedic injunction. Mā gṛdhaḥ kasya svid dhanam: "Don't touch any other property." Tena tyaktena bhuñjīthāḥ: "Whatever is given by Kṛṣṇa, God, as His prasādam, you accept it. That you can enjoy. Don't touch anything." So similarly, a person should be so nicely trained up that the one wife with religious, by performing religious ceremony, is given to him, he should be satisfied with her, not to see other women, adulteration. This is Kali-yuga. This is Kali-yuga. Now this adulteration, prostitution, is common affair, common affair. Nobody sees other's wife as his mother, nobody. And neither the woman sees other's husband as father. No.