New Revised Standard Version
And David divided the army into three groups: one third under the command of Joab, one third under the command of Abishai son of Zeruiah, Joab’s brother, and one third under the command of Ittai the Gittite. The king said to the men, “I myself will also go out with you.”

Contemporary English Version
He sent out one third of his army under the command of Joab, another third under the command of Abishai the son of Zeruiah, and the rest under the command of Ittai from Gath. He told the soldiers, "I'm going into battle with you."

New American Bible
David then divided the troops three ways, a third under Joab, a third under Abishai, son of Zeruiah and brother of Joab, and a third under Ittai the Gittite. The king said to the troops, “I intend to go out with you myself.”

Douay-Rheims Bible
And sent forth a third part of the people under the hand of Joab, and a third part under the hand of Abisai the son of Sarvia Joab's brother, and a third part under the hand of Ethai, who was of Geth: and the king said to the people: I also will go forth with you.

And sent forth a third part of the people under the hand of Joab, and a third part under the hand of Abisai the son of Sarvia Joab's brother, and a third part under the hand of Ethai, who was of Geth: and the king said to the people: I also will go forth with you.

a third part

Judges 7:16,19 And he divided the three hundred men into three parts, and gave them trumpets in their hands, and empty pitchers, and lamps within the pitchers. . . .

Judges 9:43 And he took his army, and divided it into three companies, and laid ambushes in the fields. And seeing that the people came out of the city, he arose, and set upon them,

the hand of Joab

2 Samuel 10:7-10 And when David heard this, he sent Joab and the whole army of warriors. . . .

Ittai

2 Samuel 15:19-22 And the king said to Ethai the Gethite: Why comest thou with us: return and dwell with the king, for thou art a stranger, and art come out of thy own place. . . .

I will surely

2 Samuel 17:11 But this seemeth to me to be good counsel: Let all Israel be gathered to thee, from Dan to Bersabee, as the sand of the sea which cannot be numbered: and thou shalt be in the midst of them.

Psalm 3:6 I will not fear thousands of the people surrounding me: arise, O Lord; save me, O my God.

Psalm 27:1-3 The psalm of David before he was anointed. The Lord is my light and my salvation, whom shall I fear? The Lord is the protector of my life: of whom shall I be afraid? . . .

Psalm 118:6-8 The Lord is my helper: I will not fear what man can do unto me. . . .