Manusmriti
अध्यापनमध्ययनं यजनं याजनं तथा । दानं प्रतिग्रहश्चैव षट् कर्माण्यग्रजन्मनः ॥ ७५ ॥
Teaching, studying, sacrificing for himself, sacrificing for others, making gifts and receiving them are the six acts (prescribed) for a Brahmana.
english translation
adhyApanamadhyayanaM yajanaM yAjanaM tathA । dAnaM pratigrahazcaiva SaT karmANyagrajanmanaH ॥ 75 ॥
hk transliteration by Sanscript