The Geneva Bible Translation Notes, [1599], at sacred-texts.com
(a) This was after the death of Ishbosheth Saul's son, when David had reigned over Judah seven years and six months in Hebron, (Sa2 5:5).
And this [is] the number of the mighty men whom David had; Jashobeam, an Hachmonite, the (b) chief of the captains: he lifted up his spear against three hundred slain [by him] at one time.
(b) Meaning, the most excellent and best esteemed for his valiantry: some read, the chief of the princes.
And they set themselves in the midst of [that] parcel, (c) and delivered it, and slew the Philistines; and the LORD saved [them] by a great deliverance.
(c) This act refers to Shammah, (Sa2 23:11), who it seems was the chiefest of these.
Now three of the (d) thirty captains went down to the rock to David, into the cave of Adullam; and the host of the Philistines encamped in the valley of Rephaim.
(d) That is, Eleazar and his two companions.
And said, My God forbid it me, that I should do this thing: shall I drink the (e) blood of these men that have put their lives in jeopardy? for with [the jeopardy of] their lives they brought it. Therefore he would not drink it. These things did these three mightiest.
(e) That is, this water, for which they risked their lives.
Behold, he was honourable among the thirty, but attained not to the (f) [first] three: and David set him over his guard.
(f) Meaning, those three who brought the water to David.
(g) Shammoth the Harorite, Helez the Pelonite,
(g) Called also Shammah, (Sa2 23:25).
(h) Sibbecai the Hushathite, Ilai the Ahohite,
(h) He is also called Mebunnai, (Sa2 23:27).