Musannaf Ibn Abi Shaybah

Hazrat Sha'bi says that among the Arabs, the first to write was Harb bin Umayyah bin Abd Shams. He was asked, "From where did he learn to write?" He replied, "From the people of Hira." It was asked, "From where did the people of Hira learn to write?" He replied, "From the people of Anbar."