Garudapurana 1.17.5

1.17.5

aiśānyāṃ sthāpayetsomaṃ paurandaryāṃ tu lohitam /
āgneyyāṃ somatanayaṃ yāmyāṃ caiva bṛhaspatim //

In the northeast one should place Soma, and in the east Mars;
in the southeast the son of Soma [Mercury], and in the south Bṛhaspati;