Musannaf Ibn Abi Shayba 13:3313

Abu Bakr narrated to us, he said: Jarir narrated to us, from Mughira, from Ibrahim, who said regarding the *mudarib* (the manager of a profit-sharing partnership): He passes by the tax collector (*al-'ashir*), so he gives him a gift and prepares for him a vial of oil. He said: He counts it as part of the profit. If there is no profit, then it is from the capital. He said: He bribes with the wealth to protect the wealth.