Agniveshyagrihyasutra 1.6.3.6

1.6.3.6

atha madhyamaṃ paridhimaktvā dakṣiṇārdhe ca apa upaspṛśya uttarārdhaṃ ca paristaraṇebhyo 'rdhamardhamādāya darvyāmagrayanakti madhyaṃ ca ājyasthālyāṃ mūlamanakti \

Then, having anointed the middle enclosing stick and having touched water on the southern half, taking half and half from the southern and northern halves of the surrounding grass, he anoints the tip and the middle in the ladle, and anoints the root in the ghee pot.