Qutayba's Coming to Sijistan

When Qutayba ibn Muslim was appointed over Khurasan and Sistan in the days of al-Walid ibn Abd al-Malik, he appointed his brother Amr ibn Muslim over Sistan. Rutbil demanded dirhams from him, so Qutayba came to Sistan. Al-Baladhuri relates this. ¹

The source says that Amr said he could only do what al-Hajjaj had agreed to in terms, and wrote to Qutayba about it, so Qutayba came. Rutbil sent word that they had not broken their hand from obedience, but had agreed with them on terms. ¹

Qutayba told the army to accept the terms, since it was an unlucky frontier, and they were content with them. ¹

Qutayba returned to Khurasan after sowing a crop in the land of Zaranj, to let the enemy think he had gone and so submit. When the crop was taken, the vipers prevented its use, so he ordered it burned. He left Ibn Abd Allah ibn Umayr al-Laythi as his deputy over Sistan. ¹

This report comes from a single source and needs an additional source.