This text is an edited version of the astronomical work of the 14th-century Central Asian religious scholar Sadr al-Shari`a al-Bukhari, translated and accompanied by a commentary. Sadr al-Shari`a developed the works of the 13th-century Maragha researchers, which set the tone for astronomical research until the eventual demise of Ptolemaic astronomy. This work elucidates the development and achievement of the long tradition of reforming Ptolemaic astronomy. It corroborates other evidence that scientific creativity persisted well beyond the 11th century, a period often viewed as an age of cultural decline and stagnation. Sadr al-Shari`a's knowledge of and competence in a diverse variety of disciplines is am example of the state of education and level of scholarship in a 14th-century urban setting.