Charles H. Spurgeon on Psalms 35:2

"Shield and buckler." The word rendered "shield" is in the Hebrew text מגן, magen, which was a short buckler intended merely for defence. The word rendered "buckler" is עגּה tsinnah; it was double the weight of the magen, and was carried by the infantry; the magen, being lighter and more manageable, was used by the cavalry. The tsinnah answered to the scutum, and the magen to the clypeus, among the Romans. The word tsinnah, means that kind of shield from the middle of which there arose a large boss, surmounted by a dagger, and which was highly useful both as a defensive and an offensive weapon in ancient warfare. —James Anderson, note to Calvin in loc.