Mahabharata 3.280.3

चतुर्थेऽहनि मर्तव्यमिति संचिन्त्य भामिनीव्रतं त्रिरात्रमुद्दिश्य दिवारात्रं स्थिताभवत्

caturthe'hani martavyamiti saṃcintya bhāminīvrataṃ trirātramuddiśya divārātraṃ sthitābhavat

Our plain-language meaning of this verse is waiting for scholar review.