He said before Dr Pfau's death, it had been decided that her funeral would be held on the second Saturday after her demise, as people from Pakistan and from overseas were expected to attend.
"Sister Ruth was a model of total dedication".
In 1962 Sister Ruth founded the Marie Adelaide Leprosy Centre in Karachi, Pakistan's first hospital dedicated to treating Hansen's disease, and later set up its branches in all provinces of Pakistan.
The highest ranking Catholic bishop of the Karachi diocese, Joseph Coutts, will preside over the requiem mass for Dr Pfau after the arrival of delegations and her close aides.
Harald Meyer-Porzky from the Ruth Pfau Foundation in Würzburg said Sister Pfau had "given hundreds of thousands of people a life of dignity". "He must have been my age, I was at this time not yet 30, and he crawled on hands and feet into this dispensary, acting as if this was quite normal, as if someone has to crawl there through that slime and dirt on hands and feet, like a dog".
In 1961, Sister Pfau travelled to India where she was trained in the treatment and management of leprosy.
Sister Pfau was born in Leipzig in 1929, but her childhood home was destroyed by bombing during World War II. Since 1996, the World Health Organization has considered the disease controlled in Pakistan. After the war, her family escaped the communist regime in East Germany and moved to West Germany, where Sister Pfau studied medicine.
"Well if it doesn't hit you the first time, I don't think it will ever hit you", she told the BBC in 2010 about her first encounter with leprosy.
"When you receive such a calling, you can not turn it down, for it is not you who has made the choice", she told the Express Tribune. She spent more than a half century of public service and finally went on his eternal journey. She came to Pakistan in 1960 and in 1988 she was granted Pakistani citizenship. In recognition of her services the Government of Pakistan has announced a state funeral for the German physician, also regarded as one of the most visionary social activists in Pakistan.
"It was due to her endless struggle that Pakistan defeated leprosy", the German Consulate in Karachi posted on Facebook after learning of Sister Pfau's death.
Lobel reports that it took some effort on Pfau's part to get the government to cooperate with her anti-leprosy efforts, but she eventually got its cooperation and was named the nation's federal advisor on leprosy.
Sister Pfau's funeral is scheduled for August 19 at St Patrick's Cathedral in Karachi, and she will be buried at the Christian cemetery in the city. It said her services for humanity "were nothing less than a pure manifestation of God's divine love".