Manusmriti

siva.sh/manusmriti/10/122

स्वर्गार्थमुभयार्थं वा विप्रानाराधयेत् तु सः । जातब्राह्मणशब्दस्य सा ह्यस्य कृतकृत्यता ॥ १२२ ॥

sanskrit

But let a (Sudra) serve Brahmanas, either for the sake of heaven, or with a view to both (this life and the next); for he who is called the servant of a Brahmana thereby gains all his ends.

english translation

svargArthamubhayArthaM vA viprAnArAdhayet tu saH | jAtabrAhmaNazabdasya sA hyasya kRtakRtyatA || 122 ||

hk transliteration by Sanscript