Śatapatha Brāhmaṇa ("of a hundred paths") 1.1.2.23

1.1.2.23

sa yasya gārhapatye havīṃṣi śrapayanti | gārhapatye tasya pātrāṇi saṃsādayanti jaghaneno tarhi gārhapatyaṃ sādayedyasyāhavanīye havīṃṣi śrapayantyāhavanīye tasya pātrāṇi saṃsādayanti jaghaneno tarhyāhavanīyaṃ sādayetpṛthivyāstvā nābhau sādayāmīti madhyaṃ vai nābhirmadhyamabhayaṃ tasmādāha pṛthivyāstvā nābhau sādayāmītyadityā upastha ityupastha ivainadabhārṣuriti vā āhuryatsuguptaṃ gopāyanti tasmādāhādityā upastha ityagne havyaṃ rakṣeti tadagnaye caivaitaddhaviḥ paridadāti guptyā asyai ca pṛthivyai tasmādāhāgne havyaṃ rakṣeti

In the case of one (viz. householder) whose Gârhapatya fire they (the priests) use for coking oblations, they place the utensils in the Gârhapatya (house); and let him (the Adhvaryu) in that case put (the winnowing basket with the rice) down at the back (or west) side of the Gârhapatya. But in the case of one whose Âhavanîya they use for cooking oblations, they place the utensils together in the Âhavanîya; and let him in that case put it (the rice) down at the back of the Âhavanîya. He should (in either case) do so, with the text (Vâg. S. I, 11 e), 'On the navel of the earth I place thee!' for the navel means the centre, and the centre is safe from danger: for this reason he says, 'On the navel of the earth I place thee!' And further, 'In the lap of Aditi (the boundless or inviolable earth)!' for when people guard anything very carefully, they commonly say that 'they, as it were, carried it in their lap;' and this is the reason why he says, 'In the lap of Aditi!' And further, 'O Agni, do thou protect this offering!' whereby he makes this oblation over for protection both to Agni and to this earth: for this reason he says, 'O Agni, do thou protect this offering!'