Musannaf Ibn Abi Shayba 11:225

Waki’ narrated to us, from Sufyan, from al-Zubayr ibn ‘Adi, from Shaqiq ibn al-‘Ayyzar, who said: I asked Ibn al-Zubayr about the *ja’a’il* (payments for military service). He said: "If you take them, then spend them in the way of Allah, but leaving them is better." And I asked Ibn ‘Umar, and he said: "I would not take a bribe, except for what Allah has provided me."