Skandapurana 16.19.76

16.19.76

saptamo rāvaṇasyārthe jajñe daśarathātmajaḥ ..
aṣṭame dvāpare viṣṇuraṣṭāviṃśe parāśarāt .. 76 ..

the seventh, born as the son of Daśaratha for the destruction of Rāvaṇa. / In the twenty-eighth Dvāpara, Viṣṇu was born as the eighth from Parāśara;