Amr bin Maymun (may Allah have mercy on him) narrates from Sayyiduna Umar bin al-Khattab (may Allah be pleased with him) that Uthman bin Hunayf (may Allah be pleased with him) came to him and began speaking to him from behind the tent, saying: By Allah, if you were to impose on every jarib of land one dirham and one qafiz of food, and add two dirhams on every head, that would not be hard for them nor overburden them. He said: Yes. It had been 48 dirhams, and he made it 50.
(b) Ibn Shihab (may Allah have mercy on him) narrates that Sayyiduna Umar bin al-Khattab (may Allah be pleased with him), when the people of the Sawad became wealthy, would increase their jizyah, and when they became poor, he would reduce it.
This is munqati' (broken).
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الجزية / 18684