Shiva Purana
तीक्ष्णं स परशुं लेभे निर्ददाह च तेन तान् ॥ त्रिस्सप्तकृत्वः क्षत्रांश्च प्रसन्नात्परमेश्वरात् ॥ ५७॥
He took a sharp ax and burnt them with it Three or seven times the Kshatriyas were pleased with the Supreme Lord.
english translation
tIkSNaM sa parazuM lebhe nirdadAha ca tena tAn ॥ trissaptakRtvaH kSatrAMzca prasannAtparamezvarAt ॥ 57॥
hk transliteration by Sanscript