Church of St. John 2: We already know from 15:33 that the sun
returns after the ninth hour. The God-forsakenness of Jesus from 15:34 is cancelled in 15:38: the temple, the earthly residence of God, indicates the mourning, the compassion of God.
Just as the Jew tears his garment as a sign of mourning, or at least visibly tears a piece of it, so, as a sign of divine mourning, there is a huge tear in the temple curtain, the earthly garment of God.
The grief is so great that the extremely precious fabric tears in full length and becomes worthless.