Śatapatha Brāhmaṇa ("of a hundred paths") 13.8.4.12

13.8.4.12

maryādāyā eva loṣṭamāhṛtya antareṇa nidadhātīmaṃ jīvebhyaḥ paridhiṃ dadhāmi maiṣāṃ nu gādaparo arthametam śataṃ jīvantu śaradaḥ purūcīrantarmṛtyuṃ dadhatām parvateneti jīvebhyaścaivaitām pitṛbhyaśca maryādāṃ karotyasambhedāya tasmādu haitajjīvāśca pitaraśca na sandṛśyante

Having fetched a clod from the boundary, he deposits it (midway) between (the grave and the village), with (Vâg. S. XXXV, 15), 'This I put up as a bulwark for the living, lest another of them should go unto that thing: may they live for a hundred plentiful harvests, and shut out death from themselves by a mountain!'--he thus makes this a boundary between the Fathers and the living, so as not to commingle; and therefore, indeed, the living and the Fathers are not seen together here.