Shatapatha Brahmana 3.7.2.7

3.7.2.7

sa yo varṣiṣṭhaḥ sa dakṣiṇārdhyaḥ syāt | atha hrasīyānatha hrasīyānuttarārdhyo hrasiṣṭhastathodīcī bhavati

Let the largest be the one forming the southern flank; then shorter and shorter; and the one forming the northern flank the shortest: thus (the row of stakes) inclines to the north.