They were armed with bows, and could use both the right hand and the left in hurling stones and shooting arrows out of a bow, even of Saul's brethren of Benjamin.

Bending the bow, and using either hand in hurling stones with slings, and shooting arrows: of the brethren of Saul of Benjamin.

armed with bows, using both the right hand and the left with stones and with arrows on the bow; they were of Saul's brethren of Benjamin:

armed with bow, right and left handed, with stones, and with arrows, with bows, of the brethren of Saul, of Benjamin.

They were armed with bows, and were able to send stones, and arrows from the bow, with right hand or left: they were Saul's brothers, of Benjamin.

bending the bow, and using either hand in casting stones with slings, and shooting arrows. From the brothers of Saul, out of Benjamin:

The skill of the Benjamites as archers is noted in 1-Chronicles 8:40, and 2-Chronicles 14:8. Their proficiency in using the left hand appears in the narrative of Judges (Judges 3:15, and marginal reference) where their special excellency as slingers is also noticed.
Even of Saul's brethren - Compare 1-Chronicles 12:29. Even of Saul's own tribe there were some who separated themselves from his cause, and threw in their lot with David.

[They were] armed with bows, and could use both the right hand and the left in [hurling] stones and [shooting] arrows out of a bow, [even] of Saul's (b) brethren of Benjamin.
(b) That is, of the tribe of Benjamin, of which Saul was, and in which were excellent throwers with slings, (Judges 20:16).

They were armed with bows,.... Much used in war in those times:
and could use both the right hand and the left, in hurling stones, and shooting arrows out of a bow; they were ambidextrous; who could sling stones, or shoot arrows, with either, which was no small advantage to them:
even of Saul's brethren of Benjamin; they were of the tribe of Benjamin, of which Saul was, and so his brethren; and they might be, at least some of them, his relations and kinsmen; who observing the unreasonableness of Saul's enmity to David, and detesting his cruelty, and sensible of the innocence of David, and of the service he had done his country; and perhaps not being ignorant of his divine right and title to the kingdom, went over to him, to comfort, strengthen, and assist him.

of Saul's brethren of Benjamin--that is, of the tribe of Benjamin (compare 1-Chronicles 12:29), but some of them might be relatives of the king. This movement to which the parties were led, doubtless by the secret impulse of the Spirit, was of vast importance to the cause of David, as it must have been founded on their observation of the evident withdrawal of God's blessing from Saul, and His favoring presence with David, to whom it was universally known the Divine King of Israel had given the crown in reversion. The accession of the Benjamites who came first and their resolution to share his fortunes must have been particularly grateful to David. It was a public and emphatic testimony by those who had enjoyed the best means of information to the unblemished excellence of his character, as well as a decided protest against the grievous wrong inflicted by causelessly outlawing a man who had rendered such eminent services to his country.

Even - Of Saul's own tribe: who were moved hereto by God's spirit, by the conscience of their duty to David; and by their observation of God's departure from Saul, and of his special presence with David.