Passage cross-references.

And the rest of the people he delivered into the hand of Abishai his brother, that he might put them in array against the children of Ammon.

And when the children of Ammon saw that the Syrians were fled, then fled they also before Abishai, and entered into the city. So Joab returned from the children of Ammon, and came to Jerusalem.

And David sent forth a third part of the people under the hand of Joab, and a third part under the hand of Abishai the son of Zeruiah, Joab’s brother, and a third part under the hand of Ittai the Gittite. And the king said unto the people, I will surely go forth with you myself also.

And Abishai the brother of Joab, he was chief of the three: for lifting up his spear against three hundred, he slew them, and had a name among the three. …

Then answered David and said to Ahimelech the Hittite, and to Abishai the son of Zeruiah, brother to Joab, saying, Who will go down with me to Saul to the camp? And Abishai said, I will go down with thee. …

And there were three sons of Zeruiah there, Joab, and Abishai, and Asahel: and Asahel was as light of foot as a wild roe.

So Joab and Abishai his brother slew Abner, because he had slain their brother Asahel at Gibeon in the battle.

But Amasa took no heed to the sword that was in Joab’s hand: so he smote him therewith in the fifth rib, and shed out his bowels to the ground, and struck him not again; and he died. So Joab and Abishai his brother pursued after Sheba the son of Bichri.

Whose sisters were Zeruiah, and Abigail. And the sons of Zeruiah; Abishai, and Joab, and Asahel, three.