《后汉书·列传·西域传》
皇帝于是派使者到天竺了解佛教教义，自此在中原画了佛的形像。
帝于是遣使天竺，问佛道法，遂于中国图画形象焉。
The emperor then sent envoys to India to learn about Buddhism, and since then, the image of Buddha has been drawn in the Central Plains.