In his speech On Imperial Rule (or On Monarchy), Synesius of Cyrene offers some advise to the emperor Arcadius (r.395-408). More information about this speech, together with a brief summary, can be found here.
Throughout this speech, the word "Scythians" refers to the Tervingian Germans (who would later be known as Visigoths), whereas "king" refers to emperor.
The text is offered here in the translation by A. Fitzgerald. The four-digit numbers are page numbers of the Migne edition.
On Imperial Rule 7
  And now setting forth from his own self the king will meet his friends and neighbors first. With these at his side he will take counsel concerning all matters; these he will greet as friends, with no shade of irony in the word, nor like those who gloss over what is in point of fact rough and abrupt in their despotism with a designation more kindly than the truth. After all what possession is so kingly to him as the friend at his side; what sweeter sharer in his good fortune; who surer to endure an ill turn of fortune with him; who more sincere in praise; who less apt to give pain by a biting admonition? What clearer evidence can the masses have that a king is well-disposed than his manifest power to make those about him always enviable? In this way he will gain the affection of those also who dwell afar, and it will be the prayer of good men to gain the friendship of the king.
 Exactly the reverse is the experience of tyrants, whence the witty proverb: "Far from Zeus and his thunderbolt", which means that because of such as treat their associates with treachery, safety without office is less terrifying than the dangers of public life. One has scarcely time to be envied for friendship with a tyrant before one is an object of pity by reason of his enmity.note[Cf. Augustine, Confessions 8.6.]
 Now the king knows that in God is sufficiency unto Himself, and that God, the original essence, is above the ruled over; but that with a man governing many men like himself, his own nature is sufficient to itself for the subtlety of every problem. To remedy therefore the imperfection of nature, he holds close intercourse with his friends,note[Philo, Who is Heir of Divine Things? 6.] and thereby multiplies his own power. And so he will see the eyes of all, and will take counsel from those opinions of all which tend to one conclusion.note[Cf. Dio Chrysostom, Discourse 1 and Discourse 3.]