Musannaf Ibn Abi Shayba 13:2684

Abu Bakr narrated to us, he said: Ibn Numayr narrated to us, from Abd al-Malik, from Ata, from Abu Hurayrah, who said: "Among the *suht* (ill-gotten gains) are the stud fee of a stallion, the dowry of a prostitute, and the earnings of a cupper."