The opening phrase of the prayer "Our Father who art in heaven" is not an expression specific to Christianity: it is found on several occasions in the Targums of the Pentateuch: in the Targum Neophyte and the Targum Pseudo-Jonathan, but also and above all, in the fragmentary Targums. This communication will show that Jesus' use of this expression in Matthew, particularly in the Discourse on the Mount (Matt 6-7), is part of the same impetus as that used in the Targums, while referring to dimensions that are properly Christological. Some authors wrote already on this (among all Shrenk, Hayward, Jeremias, Marchel), but never on an exhaustive manner; there is therefore a place for a synthesis of their arguments, that still need to be fleshed out. The method employed consists first of all in comparing the literary use of the expression “your, his, her, their father in Heaven” in the Targums. The sections concerned are : Gen 21:33 (Abraham at Abimelech's); Ex 1:19.21 (the women in labour and the midwives); Ex 15:12 (the Earth swallowing the ennemies); Ex 17:11 (the battle against Amalek); Num 20:21 (the Edom territory bypassing) ; Num 21:9 (the brazen serpent); Num 23:23 (Balaam's oracle); Deut 28:32 (the sons and daughters taken away); Deut 32:6 (various curses); Deut 33:24 (the blessing of Asher). After that, we need to have a look on the use of the same expression in the Gospel of Matthew: its literary context, the effect on the characters and the commitment induced.
Naveau et al. (Mon,) studied this question.