" 6:9-10. Greek sources often called the supreme deity “father,” including in prayers, but this practice is pervasive in Jewish sources as well, even as early as the *Old Testament (Deut 32:6; Ps 68:5; Is 63:16; 64:8; Jer 3:4, 19; 31:9; Mal 1:6; 2:10) and other very early Jewish works (e.g., Tobit 13:4; *3 Maccabees 5:7; 7:6). "

― Craig S. Keener , The IVP Bible Background Commentary: New Testament