Śatapatha Brāhmaṇa ("of a hundred paths") 6.7.3.5

6.7.3.5

yadevam pratyavarohati | etadvā etadimāṃlokānita ūrdhvo jayati sa sa parāṅiva jayo yo vai parāṅeva jayatyanye vai tasya jitamanvavasyantyatha ya ubhayathā jayati tasya tatra kāmacaraṇam bhavati tadyatpratyavarohatīmānevaitallokānitaścordhvānamutaścārvāco jayati

And, again, why he lowers it,--there, indeed, in rising upwards, he conquers these worlds from here: that is, as it were, a conquering in a forward direction. Now the conquest of him who conquers only in a forward direction is completed by others; but for him who conquers both ways there is free scope: thus, when he lowers (the fire) he conquers these worlds both from here upwards and from thence backwards.