सतीविवाहवर्णनं नाम विन्शोऽध्यायः
Sati marriage description Chapter 20
चैत्रशुक्लत्रयोदश्यां नक्षत्रे भगदैवते |
सूर्यवारे च यो भक्त्या वीक्षेत भुवि मानवः || 38 ||
तदैव तस्य पापानि प्रयान्तु हर संक्षयम् |
वर्द्धतां विपुलं पुण्यं रोगा नश्यन्तु सर्वशः || 39 ||
Shiva, in the constellation of Uttar Falguni on Sunday, Chaitra shukla thirteenth, one who looks at the earth/ground with devotion, his sins will disappear, a lot of punya will increase and all diseases will be destroyed just then.
This is a part of the boon asked for by Lord Brahma. The marriage with Sati took place in the constellation of Uttar Falguni on Sunday, Chaitra shukla thirteenth.