MuU 1.2.1
तदेतत् सत्यं मन्त्रेषु कर्माणि कवयो यान्यपश्यंस्तानि त्रेतायां बहुधा संततानि । तान्याचरथ नियतं सत्यकामा एष वः पन्थाः सुकृतस्य लोके
tadetat satyaṃ mantreṣu karmāṇi kavayo yānyapaśyaṃstāni tretāyāṃ bahudhā saṃtatāni | tānyācaratha niyataṃ satyakāmā eṣa vaḥ panthāḥ sukṛtasya loke
Sanskrit for this text is pending; the English follows the translator's numbering.
This is the truth: the sacrificial works which they (the poets) saw in the hymns (of the Veda) have been performed in many ways in the Tretâ age. Practise them diligently, ye lovers of truth, this is your path that leads to the world of good works!
Translated by F. Max Müller