Mahabharata 3.214.1

3.214.1

mārkaṇḍeya uvāca |
śivā bhāryā tvaṅgirasaḥ śīlarūpaguṇānvitā |
tasyāḥ sā prathamaṃ rūpaṃ kṛtvā devī janādhipa |
jagāma pāvakābhyāśaṃ taṃ covāca varāṅganā || 1 ||

"Markandeya continued, 'O lord of men, the beautiful Siva endowed with great virtues and an unspotted character was the wife of Angiras (one of the seven Rishis). That excellent lady (Swaha) at first assuming the disguise of Siva, sought the presence of Agni unto whom she said, 'O Agni, I am tortured with love for thee. Do thou think it fit to woo me. And if thou dost not accede to my request, know that I shall commit self-destruction. I am Siva the wife of Angiras. I have come here according to the advice of the wives of the other Rishis, who have sent me here after due deliberation.'