فضل الله الصمد في توضيح الأدب المفرد للجيلاني

Fadhlullahus Samad fee Tawdheehil Adabil Mufrad

Imam Bukhari complied a separate book that deals with Islamic Mannerism. In this link you will find one of the best available and important commentaries on this book written by Maulana Fadhlullah al-Jilaani (May Allah have mercy on him).