Skandapurana 16.25.34

16.25.34

aṣṭame somavāre tu amoghāyutamīśvaram ..
kadalīphalakenārghyaṃ marubakena pūjayet ..
rātrau tu prāśayeddugdhamagniṣṭomaphalaṃ labhet .. 34 ..

On the eighth Monday, [one should worship] Īśvara accompanied by Amoghā; / one should offer the water-offering with a plantain fruit and worship with marubaka; / at night one should consume milk; one obtains the fruit of the Agniṣṭoma sacrifice.