They were bowmen and could shoot arrows and sling stones with either the right or the left hand; they were Benjaminites, Saul’s kinsmen.
We have here an account of those that appeared and acted as David's friends, upon the death of Saul, to bring about the revolution. All the forces he had, while he was persecuted, was but 600 men, who served for his guards; but, when the time had come that he must begin to act offensively, Providence brought in more to his assistance.
Commenting on 1 Chronicles 12:1-22
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...
of Saul's brethren of Benjamin--that is, of the tribe of Benjamin (compare Ch1 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...