Shiva Purana
तत्र त्वं गच्छ नभग तान् सुशंस महाकवे ॥ सूक्ते द्वे वैश्वदेवे हि सत्रं शुद्धं हि तद्भवेत् ॥ १९॥
O wise Nabhaga, you go there and praise them. Recite two Vaiśvadeva sūkatas there. That sacrifice will then become perfect.
english translation
tatra tvaM gaccha nabhaga tAn suzaMsa mahAkave ॥ sUkte dve vaizvadeve hi satraM zuddhaM hi tadbhavet ॥ 19॥
hk transliteration by Sanscript