He finished his book in 1030 CE. He called it Kitab fi Tahqiq ma li'l-Hind —"The Book of Verifying What Belongs to India." It had 80 chapters covering: Hindu religion, caste, marriage, astronomy, geometry, medicine, law, festivals, and even the game of chess.
The Sultan laughed. "What is there to learn from a conquered land?"
Once he understood the language, Al-Biruni began writing. He did not write to praise or to condemn India. He wrote to describe it. He used a brilliant method: he would explain a Hindu idea, then immediately compare it to a similar idea from Greek philosophy or Islamic science. kitab al hind
Al-Biruni smiled. "A mirror does not judge the face it reflects. It simply shows it clearly. If I only see them through my own eyes, I will write a book of my own prejudices. I want to write a book of their truth."
Al-Biruni was stung but not defeated. He went home and did something no other Muslim scholar of his time had done. Not just a few phrases, but deeply—grammar, poetry, philosophy. He spent years reading the Puranas , the Bhagavad Gita , and the works of Aryabhata (the mathematician). He finished his book in 1030 CE
Kitab al-Hind was not a bestseller in its time. Conquerors wanted maps of India’s treasure, not maps of its mind. But centuries later, historians realized: Al-Biruni had done something revolutionary. He had written the first objective, empathetic, and scholarly study of a civilization by an outsider.
Al-Biruni was not interested in treasure. When the Sultan returned from his raids, Al-Biruni asked only for one thing: "What is there to learn from a conquered land
Here’s a short, useful story to help understand and remember the significance of Kitab al-Hind (meaning "The Book of India"), written by the scholar Al-Biruni in 1030 CE. The Scholar Who Listened to the Waves
Al-Biruni replied, "A river does not conquer the rock it flows over, Your Majesty. It understands it."