Graca Machel: Nelson Mandela’s wife thanks well-wishers

Nelson Mandela's wife, Graca Machel, is thanking the thousands of people worldwide who have wished the former president well during his hospital stay.

Machel, Mandela's third wife whom he married on his 80th birthday, said in a statement Monday that the messages "from South Africans, Africans across the continent, and thousands more from across the world" had lightened "the burden of anxiety" and brought "love, comfort and hope."

She said the world had "stood with him, making a difference to him in his healing" and that "our gratitude is difficult to express."

People have been carrying "get well soon" signs outside the Mediclinic Heart Hospital in Pretoria, where Mandela, 94, is being treated for a recurring lung infection. Prayers have also been said for South Africa's first black president across the nation and schoolchildren have gone to his home in Johannesburg to sing.

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"The messages have come by letter, by SMS, by phone, by Twitter, by Facebook, by email, cards, flowers and the human voice, in particular the voices of children in schools or singing outside our home," Machel said in a statement. "We have felt the closeness of the world and the deepest meaning of strength and peace."

The Nobel Peace Prize winner, in the hospital for the third time this year, is believed to have suffered damage to his lungs while working in a prison quarry. He contracted tuberculosis in the 1980s when held in a jail on Robben Island.