SB 8.12.15
sri-bhagavan uvaca
kautuhalaya daityanam
yosid-veso maya dhrtah
pasyata sura-karyani
gate piyusa-bhajane
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
The Supreme Personality of Godhead said: When the demons took away the jug of nectar, I assumed the form of a beautiful woman to bewilder them by directly cheating them and thus to act in the interest of the demigods.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
When the Supreme Personality of Godhead assumed the form of the beautiful woman Mohini-murti, the demons were certainly captivated, but the demigods present were not. In other words, those who maintain a demoniac mentality are bewildered by the beauty of a woman, but those who are advanced in Krsna consciousness, or even those on the platform of goodness, are not bewildered. The Supreme Personality of Godhead knew that because Lord Siva is not an ordinary person, he cannot be bewildered even by the most beautiful woman. Cupid himself tried to invoke Lord Siva’s lusty desires in the presence of Parvati, but Lord Siva was never agitated. Rather, the blazing fire from Lord Siva’s eyes turned Cupid to ashes. Therefore, Lord Visnu had to think twice about what kind of beautiful form would bewilder even Lord Siva. Consequently He was smiling gravely, as stated in the previous verse (prahasya bhava-gambhiram). A beautiful woman generally cannot induce Lord Siva to be lusty, but Lord Visnu was considering whether there was any form of woman who could enchant him.