Vermes writes (on pp. 177-178):
The formula "my Father who is in heaven" occurs also in Midrashic
texts almost automatically in first person speech. Thus at the end of
his famous exposition of Exodus 20:6, "of them that love me and keep
my commandments" as referring to Jewish martyrs of the Hadrianic
persecution, after quoting Zechariah 13.6 the early second-century R.
"These words caused me to be loved by my Father who is in heaven"
(Mekh on Ex. 20:6, Lauterbach II, 247). Another striking example
figures in Sifra on Leviticus (ed. Weiss 93b):
R. Eleazar ben Azariah said: Let no-one declare, 'I do not desire . .
. swine flesh or forbidden sex, but one must say, although I desire
them, what shall I do since my Father who is in heaven has given me
For texts where individuals are portrayed as addressing God as "my
Father," in Second Temple Judaism, see Marianne M. Thompson's The
Promise of the Father (pp. 48-53).
See Vermes' work at http://www.amazon.com/The-Religion-Jesus-Geza-Vermes/dp/0800627970