The Church of All Nations on the Mount of Olives, where we commemorate the Lord’s agony in the garden.
The inscription at the base of the image is from Luke 23:43-44:
Apparuit autem illi angelus de caelo confortans eum et factus in agonia prolixius orabat et factus est sudor eius sicut guttae sanguinis decurrentis in terram.
And there appeared to him an angel from heaven, strengthening him. And being in an agony, he prayed the longer. And his sweat became as drops of blood, trickling down upon the ground.
The windows are alabaster. From Wikipedia, “Alabaster panels dyed violet were used for the windows to evoke a mood of depression analogous to Christ’s agony, and the ceiling is painted a deep blue to simulate a night sky.”