Arnobius, 5.7. Lancelotti, p. 51 n. 177, interprets the Mother of the gods actions here as allowing 'Agdistis to make Attis insane and be driven to suicide.' Concluding that thus 'the death of Attis is not accidental but planned and intended by the Great Mother, who only in this way can "save him"'.
For example, an altar at Sizma depicts Agdistis, the Great Mother, Apollo Sozon, and Helios, each in relief on one of its four sides, see Sfameni Gasparro, p. 35.
