Ramayana
मासं स स्त्री तदा भूत्वा रमयत्यनिशं शुदा । मासं पुरुषभावेन धर्मबुद्धिं चकार सः ॥ 7-89-22 ॥
For one month, becoming a woman then, she sported ceaselessly with delight; and for the next month, with the nature of a man restored, he turned his mind to righteousness.
english translation