Matsya Purana 223.8

223.8

antaḥ kopo bahiḥ kopo yatra syātāṃ mahīkṣitām.
antaḥ kopo mahāṃstatra nāśakaḥ pṛthivīkṣitām .. 223.7 ..

In an Empire there are two sources from which bitter feelings of anger and enmity crop up, one is internal and the other external of these, the internal faction is most to be dreaded, for it is this internal faction that brings about the ruin of kings. The source of anger and enmity coming from outside from other kings is known as external source of danger. The queen, prince, commander-in-chief, ministers, prime minister, the princes the wrath and discontent of these are known as the internal source of wrath and danger. To a king this is indeed terrible. If the internal condition of the Empire be good and satisfactory, then the external source of danger however great, can be easily conquered by a king. He easily wins victory—7-10