What is the connection between a hamam and a vakıf?
A vakıf is a charitable endowment. Some Ottoman baths generated income for foundations supporting institutions such as religious, educational or social facilities.

Related questions
Why were hamams important in Ottoman daily life?
Hamams provided a place to wash and meet others. Their social role included conversation and celebrations as well as everyday bathing.
How old is the Bayezid Hamam in Istanbul?
The museum's official account dates construction to 1507–1508 using archival evidence. It is now a place to learn about bath culture, rather than book a wash.
Did Mimar Sinan design hamams in Istanbul?
Yes. Sinan's work includes Istanbul bath architecture, including Zeyrek Çinili Hamam. Do not assume every domed hamam was designed by him.