|Easton's Bible Dictionary|
(1.) A Meholathite, the father of Adriel (2 Samuel 21:8).
(2.) A Gileadite of Rogelim who was distinguished for his loyalty to David. He liberally provided for the king's followers (2 Samuel 17:27). David on his death-bed, remembering his kindness, commended Barzillai's children to the care of Solomon (1 Kings 2:7).
(3.) A priest who married a daughter of the preceding (Ezra 2:61).
Int. Standard Bible Encyclopedia
bar-zil'-a-i, bar-zil'-i (barzillay; Berzelli, "man of iron" (BDB, but compare Cheyne, Encyclopedia Biblica)):
(1) A Gileadite of Rogelim who brought provisions to David and his army to Mahanaim, in their flight from Absalom (2 Samuel 17:27-29). When David was returning to Jerusalem after Absalom's defeat, Barzillai conducted him over Jordan, but being an old man of 80 years of age, he declined David's invitation to come to live in the capital, and sent instead his son Chimham (2 Samuel 19:31-39). David before his death charged Solomon to "show kindness unto the sons of Barzillai." (1 Kings 2:7). Cheyne in Encyclopedia Biblica, without giving any reason, differentiates this Barzillai from Barzillai the Gileadite (Ezra 2:61 = Nehemiah 7:63). See (2) below.
(2) The father of a family of priests who in Ezra's time, after the return of the exiles, could not trace their genealogy. "Therefore were they deemed polluted and put from the priesthood." This Barzillai had taken "a wife of the daughters of Barzillai the Gileadite," and had adopted his wife's family name (Ezra 2:61, 62 = Nehemiah 7:63, 64). His original name is given as Jaddus (the King James Version Addus) (1 Esdras 5:38). (See ZORZELLEUS; the Revised Version, margin "Phaezeldaeus.")
(3) Barzillai the Meholathite, whose son Adriel was married to Saul's daughter, either Michal (2 Samuel 21:8) or Merab (1 Samuel 18:19).
Barzillai (10 Occurrences)
2 Samuel 17:27 It happened, when David was come to Mahanaim, that Shobi the son of Nahash of Rabbah of the children of Ammon, and Machir the son of Ammiel of Lodebar, and Barzillai the Gileadite of Rogelim, (WEB KJV JPS ASV BBE DBY WBS YLT NAS NIV)
2 Samuel 19:31 Barzillai the Gileadite came down from Rogelim; and he went over the Jordan with the king, to conduct him over the Jordan. (WEB KJV JPS ASV BBE DBY WBS YLT NAS NIV)
2 Samuel 19:32 Now Barzillai was a very aged man, even eighty years old: and he had provided the king with sustenance while he lay at Mahanaim; for he was a very great man. (WEB KJV JPS ASV BBE DBY WBS YLT NAS NIV)
2 Samuel 19:33 The king said to Barzillai, "Come over with me, and I will sustain you with me in Jerusalem." (WEB KJV JPS ASV BBE DBY WBS YLT NAS NIV)
2 Samuel 19:34 Barzillai said to the king, "How many are the days of the years of my life, that I should go up with the king to Jerusalem? (WEB KJV JPS ASV BBE DBY WBS YLT NAS NIV)
2 Samuel 19:39 All the people went over the Jordan, and the king went over. Then the king kissed Barzillai, and blessed him; and he returned to his own place. (WEB KJV JPS ASV BBE DBY WBS YLT NAS NIV)
2 Samuel 21:8 But the king took the two sons of Rizpah the daughter of Aiah, whom she bore to Saul, Armoni and Mephibosheth; and the five sons of Michal the daughter of Saul, whom she bore to Adriel the son of Barzillai the Meholathite. (WEB KJV JPS ASV BBE DBY WBS YLT NAS NIV)
1 Kings 2:7 But show kindness to the sons of Barzillai the Gileadite, and let them be of those who eat at your table; for so they came to me when I fled from Absalom your brother. (WEB KJV JPS ASV BBE DBY WBS YLT NAS NIV)
Ezra 2:61 Of the children of the priests: the children of Habaiah, the children of Hakkoz, the children of Barzillai, who took a wife of the daughters of Barzillai the Gileadite, and was called after their name. (WEB KJV JPS ASV BBE DBY WBS YLT NAS NIV)
Nehemiah 7:63 Of the priests: the children of Hobaiah, the children of Hakkoz, the children of Barzillai, who took a wife of the daughters of Barzillai the Gileadite, and was called after their name. (WEB KJV JPS ASV BBE DBY WBS YLT NAS NIV)