Eliot's friend Mary Trevelyan proposed to him a few times after the death of Eliot's first wife. According to Carole Seymour-Jones, (p. 651) this is the prayer that she said for Eliot each night:
Protector of travellers
Bless the road.
Watch over him in the desert.
Watch over him in the mountain.
Watch over him in the labyrinth.
Watch over him by the quicksand.
Protect him from the Voices
Protect him from the Visions
Protect him from the tumult
Protect him in the silence.
For the prayer Seymour-Jones cites the postscript to Trevelyan's unpublished memoir of Eliot The Pope of Russell Square 1938-1958.
As for the Voices and Visions mentioned in the prayer, Seymour-Jones also mentions that Eliot had auditory and visual hallucinations (pp. 288-9, 443-4, 467), Again she cites The Pope of Russell Square 1938-1958, notably chapter 22.