Skandapurana 5.251.37

5.251.37

śamī śanaiścareṇātha svīkṛtā śūdrajātibhiḥ..
rāhuṇā svīkṛtā dūrvā pitṝṇāṃ tarpaṇocitā..37..

the śamī by Śanaiścara and adopted by the Śūdra castes; / the dūrvā grass, suitable for offering oblations to the ancestors, is adopted by Rāhu;