In a subsequent communication, Hajjaj reiterated that all able-bodied men were to be killed, and that their underage sons and daughters were to be imprisoned and retained as hostages. Qasim obeyed, and on his arrival at the town of Brahminabad massacred between 6,000 and 16,000 men.
The significance of these events lies not just in the horrible numbers involved, but in the fact that the perpetrators of these massacres were not military thugs disobeying the ethical teachings of their religion, as the European crusaders in the Holy Land were, but were actually doing precisely what their religion taught. (And one may note that Christianity has grown up and no longer preaches crusades. Islam has not. As has been well-documented, jihad has been preached from the official centers of Islam, not just the lunatic fringe.)
Qasim's early exploits were continued in the early eleventh century, when Mahmud of Ghazni, "passed through India like a whirlwind, destroying, pillaging, and massacring," zealously following the Koranic injunction to kill idolaters, whom he had vowed to chastise every year of his life.
In the course of seventeen invasions, in the words of Alberuni, the scholar brought by Mahmud to India, "Mahmud utterly ruined the prosperity of the country, and performed there wonderful exploits, by which the Hindus became like atoms of dust scattered in all directions, and like a tale of old in the mouth of the people. Their scattered remains cherish, of course, the most inveterate aversion toward all Moslems."
Does one wonder why? To this day, the citizens of Bombay and New Delhi, Calcutta and Bangalore, live in fear of a politically-unstable and nuclear-armed Pakistan that unlike India (but like every other Moslem country) has not managed to maintain democracy since independence.