With his armour; either,
1. With Saul's own armour which he used to wear in battle; which seems not to agree with the extraordinary height of Saul's stature, 1 Samuel 10:23; nor is it like that Saul would disarm himself, when he was going forth to the battle, 1 Samuel 17:20,21. Or,
2. With armour taken out of his armoury. Not that the whole armory of Saul was brought into the field; but that some chosen arms were taken out thence, and brought for any emergent occasion. Or rather, 3. With his vestments, or garments. For,
1. So the Hebrew word properly and usually signifies; and so this same word is translated, 1 Samuel 18:4.
2. His armour is distinguished from this, and is particularly described in the following words. He seems therefore to speak of some military vestments which were then used in war, and were contrived for defence; such as buff-coats now are.