Musannaf Ibn Abi Shaybah

Hasan says that there is no jizya on this.

Ibrahim says that if a man frees a Christian slave, then jizya is due upon him.

Hazrat Sinan narrates that Hazrat Umar bin Abdul Aziz used to collect jizya from that Christian slave who had been freed by a Muslim.

Hazrat Amr bin Maimoon narrates that I asked Hazrat Umar bin Abdul Aziz regarding Kharaji land, whether there is (also) Zakat on it? He replied, "Kharaj is on the land, and Zakat is on its produce (crops, etc.)."