ABIATHAR ("Father of Plenty").
A son of Ahimelech or Ahijah (melech and yah apparently interchanging; compare I Sam. xiv. 3, xxii. 9); the chief priest of the sanctuary at Nob. He alone escaped from the massacre of his family by Saul (I Sam. xxii. 20) and found a refuge with David. By means of the priestly ephod which he brought with him, he was able officially to ascertain the will of YHWH (I Sam. xxiii. 9, xxx. 7). Having shared David's hardships, he also profited by the exaltation of David to the kingship. At the time of Absalom's rebellion Abiathar remained loyal to his old patron (II Sam. xv. 24-36); but later, like Joab, he espoused the cause of Adonijah rather than that of Solomon. On this account he and his family were banished to their estate at Anathoth, and their priestly rights and duties in connection with the Temple were transferred to the rival house of Zadok (I Kings, ii. 26-33).
The rescue of the chief priest Abiathar, in the massacre of the priests of Nob ordered by Saul, was fortunate for the house of David; for if he had lost his life, David's descendants would through divine retaliation have been entirely wiped out of existence at the hands of Athaliah (Sanh. 95b). It was David's acts that had really brought about the death of the priests, and to make amends he appointed Abiathar high priest. Abiathar retained the office until he was deserted by the Holy Spirit, without which the high priest could not successfully consult the Urim and Thummim. When David, on his flight from Absalom, recognized this loss in Abiathar, he felt compelled to put Zadok in his place. See Seder 'Olam R. xiv.; Yoma, 73b; Soṭah, 48b; Ber. 4a (Rashi); Sanh. 21a. Compare also Ginzberg, "Haggada bei den Kirchenvätern," i., on II Sam. xv. 24, 25.