Ibn Khordadbeh
Medieval Muslim scholars, including 9th-10th century geographers Ibn Khordadbeh and Istakhri, narrated that the Khalaj were one of the earliest tribes to have crossed the Amu Darya from Central Asia and settled in parts of present-day Afghanistan, especially in the Ghazni, Qalati Ghilji (also known as Qalati Khalji), and Zabulistan regions. Mid-10th-century book "Hudud al-'Alam" described the Khalaj as sheep-grazing nomads in Ghazni and the surrounding districts, who had a habit of wandering through seasonal pastures.