Abdur Razzaq was a Persian ambassador who visited the Vijayanagar Empire during the reign of King Devaraya II in the early 15th century. In his travelogue titled "Matla-us-Sadain wa Majma-ul-Bahrain" (Rise of the Two auspicious constellations and the Confluence of the Two Seas), he has described various aspects of the empire's administration, society, and economy.

One of the interesting observations made by Abdur Razzaq is about the source of revenue for paying the salaries of policemen in Vijayanagar. He writes that the income of the prostitutes in the brothels was used to pay the wages of the policemen. This may seem surprising or even shocking to some readers, but it was a common practice in many ancient and medieval societies to tax or regulate prostitution as a source of income for the state or the ruling class.

Let us break down this answer into headings and HTML bullet points for better clarity:

Abdur Razzaq's observation:
- Persian ambassador who visited Vijayanagar Empire in 15th century
- Wrote a travelogue titled "Matla-us-Sadain wa Majma-ul-Bahrain"
- Described various aspects of empire's administration, society, and economy

Source of revenue for policemen's salaries:
- According to Abdur Razzaq, policemen's pay in Vijayanagar came from the proceeds of brothels
- Prostitution was taxed or regulated in many ancient and medieval societies as a source of income for the state or ruling class
- This may seem surprising or shocking to some readers, but it was a common practice in those times

Other possible sources of revenue:
- It is possible that Vijayanagar also collected taxes on goods, land revenue, or wine shops to fund other expenses
- However, Abdur Razzaq's specific mention of brothels suggests that it was the primary or at least a significant source of income for the policemen's salaries

Conclusion:
- Abdur Razzaq's travelogue provides valuable insights into the socio-economic conditions of Vijayanagar Empire
- While some of his observations may seem unfamiliar or even uncomfortable to modern readers, they reflect the realities of the past and the diversity of human cultures