Manasara 7.57

7.57

dakṣiṇe rasapadaṃ caiva vivasvān eva kathyate
paścime ṣaṭpadaṃ caiva mitrasya miti saṃsmṛtam

six plots in the south is declared [the place] of Vivasvat; / six plots in the west is remembered as the measure for Mitra;