Nelson Mandela's health is improving but his doctors say he will continue to receive treatment for a recurrence of pneumonia.
The 94-year old former South African president and anti-apartheid hero was admitted to hospital late on Wednesday.
In a statement on Sunday evening, South Africa's presidency said he had a "restful day" and is continuing to receive treatment as he spends a fifth night in the unnamed hospital.
There are no details yet on much longer he will stay there, the BBC reports.
Churches across the country have held prayers for Mr Mandela, including the Regina Mundi church in Soweto - once a focal point of the anti-apartheid struggle.
Another service at Midvaal, south of Johannesburg, was attended one of his grand-daughters, Ndileka Mandela.
President Jacob Zuma thanked the "thousands" of South Africans who had prayed for him.
Nelson Mandela first contracted tuberculosis in the 1980s while detained on Robben Island. His lungs are said to have been damaged while working in a prison quarry.
He served as South Africa's first black president from 1994 to 1999 and is regarded by many as the father of the nation for leading the struggle against apartheid.