Adam Clarke Bible Commentary

Thy cloak - thy coat - In Mat 5:40, I have said that Coat, χιτωνα, signifies under garment, or strait coat; and Cloak, ἱματιον, means upper garment, or great coat. This interpretation is confirmed by the following observations of Bishop Pearce. The χιτων was a tunica, or vestcoat, over which the Jews and other nations threw an outer coat, or gown, called a cloak, Mat 5:40, (which is meant by ἱματιον), when they went abroad, or were not at work. Hence the common people at Rome, who did not usually wear, or had no right to wear, the toga, are called by Horace tunicatus popellus, Epist. i. 7, 65. This account of the difference between the χιτων and the ἱματιον appears plainly from what Maximus Tyrius says, The inner garment which is over the body they call χιτωνισκον, and the outer one the ἱματιον. And so Plutarch, (in Nupt. p. 139, ed. Fran. 1620), speaking of a man who felt the heat of the sun too much for him, says that he put off, τον χιτωνα, τῳ ἰματιῳ, his vestcoat also with his cloak.