(59) Cf. "Our Father which is in Heaven" of the "Lord's Prayer" (Matt. VI, 9). The conception of God as a "Father" goes back to earliest times. See Gen. XLIX, 19, 20; Ex. IV, 22; Deut. XXXII, 6; II Sam. V, 44; Ps. LXXXIX, 27, 28; Isa. LXIII, 16, LXIV, 8, and Mal. II, 10. Deut. XXXII, 6, reads, "Is He not thy Father?" and Isa. LXIII, 18, "Doubtless Thou art our Father." In the _Mishnah_ we find, "Who purifies you? Your Father which is in Heaven" (_Yoma_ VII, 8); "On whom have we to lean? On our Father which is in Heaven" (_Sotah_, IX, 15), and similar passages. The Rabbis constantly referred to God as "Father" (see Schechter, _Aspects_, pp. 46, 49, 50-51). They took issue, of course, with the New Testament conception of God, in not admitting and in denouncing the idea of a mediator. To them all mankind were the sons of God. That the Rabbis borrowed this God-idea and the expression "Our Father which is in Heaven" from Christianity is untenable, for, as Herford (_Pharisaism_, 120 _et seq._) points out, such borrowing would have been abhorrent to them. This expression was undoubtedly current long before and during the time of Jesus, and it represented a conception of the divine acceptable to both the Rabbis and Jesus. The Rabbis had no quarrel with Christianity on this score, but did not admit the "sonship" of God in the Christian sense. The expressions "Our Father" and "Our Father which is in Heaven" are found frequently in the Jewish Prayer-book. On this subject, consult Taylor, _Sayings_, pp. 124, 176, and G. Friedlander, _The Jewish Sources of the Sermon on the Mount_, chapter X. For a comparison of other parts of _Abot_ with the New Testament see Feibig, _Pirque 'aboth_, especially the _Nachwort_, pp. 42-43, and G. Friedlander, _ibid._, _passim_. It seems that originally _Abot_ ended here, as in the _Machzor Vitry_. The verses which follow were added from other sources. See Bacher, _Agada der Tanaiten_, I, 378; Taylor, _ibid._, p. 95, n. 46, p. 96, n. 47; Hoffmann, _Die erste Mischna_, p. 30; _idem_, _Abot_, p. 358, notes 106 and 108; and Strack, _Spruche_, p. 46, notes _t_ and _u_. (60) Taylor makes this verse an _addendum_ to chapter V, and calls it "The Ages of Man." Cf. Shakespeare's "Seven Ages of Man." See in the _Jewish Encyclopedia_, art. _Ages of Man in Jewish Literature_, _The Seven_, and Schechter, _Studies_, I, pp. 299-300.