Srimad-Bhagavatam: Canto 10 - Chapter 1 - Verse 5
Sanskrit:
एवं यदूनां शाल्वानां निघ्नतामितरेतरम् ।युद्धं त्रिनवरात्रं तदभूत्तुमुलमुल्बणम् ॥ ५ ॥
ITRANS:
evaṁ yadūnāṁ śālvānāṁnighnatām itaretaramyuddhaṁ tri-nava-rātraṁ tadabhūt tumulam ulbaṇam
Translation:
As the Yadus and Śālva’s followers thus went on attacking one another, the tumultuous, fearsome battle continued for twenty-seven days and nights.