Ammianus Marcellinus Res Gestae 18.8.5

[5] Finally, after it became absolutely necessary to resort to arms, while we were hesitating as to what ought to be done, some of our men ran forward rashly and were killed. And as both sides pressed forward, Antoninus, who was ostentatiously leading the troops, was recognised by Ursicinus and rated with chiding language; and after being called traitor and criminal, Antoninus took off the tiara which he wore on his head as a token of high honour, sprang from his horse, and bending his body so that he almost touched the ground with his face, he saluted Ursicinus, calling him patron and lord, clasping his hands together behind his back, which among the Assyrians is a gesture of supplication.