Śatapatha Brāhmaṇa ("of a hundred paths") 13.8.1.2

13.8.1.2

tadvai na kṣipraṃ kuryāt nennavamaghaṃ karavāṇīti cira eva kuryādaghameva tattiraḥ karoti yatra samānānu cana smareyuraśrutimeva tadaghaṃ gamayati yadyanusmareyuḥ

Let him not make it too soon (after the deceased man's death) lest he should freshen up his sin; but let him make it a long time after, as thereby he obscures the sin;--and when people do not even remember the years (that have passed), as thereby one causes the sin to pass into oblivion. If they do remember,--