Samvartta Smriti 162

162

sakhibhāryyāṃ kumārīñca śvaśrūṃ vā śyālikāṃ tathā
niyamasthāṃ vratasthāñca yo'bhigacchetstriyaṃ dvijaḥ
sa kuryyātprākṛtaṃ kṛcchraṃ dhenuṃ dadyātpayasvinīm

If a twice-born man has intercourse with a friend's wife, a maiden, a mother-in-law, a sister-in-law, / or a woman observing a restriction or performing a vow, / he should perform an ordinary Kṛcchra penance and give a milch cow.