MUHTASIB محتسب
The public censor of religion and morals, who is appointed by a Muslim ruler to punish Muslims for neglecting the rites of their religion.
Sir Alexander Burnes, in his Travels in Bokhara (vol. i. p. 313), relates that tie saw persons publicly scourged because they had slept during prayer-time and smoked on Friday. [DIRRAH.]
Burckhardt, in his account of the Wahhabis (vol. ii p. 146), says, the neglect of religious duty is always severely punished. When Sa’ud took al-Madinah, he ordered some of his people after prayers in the mosque to call over the names of all the grown up inhabitants of the town who were to answer individually. He then commanded them to attend prayers regularly; and if any, one absented himself two or three times, Sa’ud sent some of his Arabs to beat the man in his own house. At Makkah, when the hour of prayer arrived, he ordered the people to patrol the streets, armed with large sticks, and to drive all the inhabitants by force into the mosque; a harsh proceeding, but justified by the notorious irreligion of the Makkans.
Dr. Bellow, in his Kashmir and Kashgar (p. 281), gives an animated account of the way in which the Mubtasib performed his duties in the streets of Kashgar.

Based on Hughes, Dictionary of Islam