Agni Purana (Jyotisha Selections) · by Vyasa
Chapter 6 · Travel Muhurta
यात्रामण्डलचिन्ता
आत्ममण्डलमेवात्र प्रथमं मण्डलं भवेत् ।सामन्तास्तस्य विज्ञेया रिपवो मण्डलस्य तु ॥ १४ ॥
In the full Agni Purana this is chapter 233, verse 14.
Here, one's own circle is the first circle. Its border kings should be known as the enemies of the circle.
Simple meaning: The king's own land is the first circle. The kings on its border are its enemies.
उपेतस्तु सुहृज्ज्ञेयः शत्रुमित्रमतः परम् ।
Know the friend, then the enemy's friend, then the friend's friend, then that one's enemy.
एतत्पुरस्तात्कथितं पश्चादपि निबोध मे ।
Now hear about the kings behind: first the enemy at the rear, then the ally at the rear.
आसारस्तु ततोऽन्यः स्यादाक्रन्दासार उच्यते ।
Behind the king come the rear enemy's helper and the rear ally's helper.