Musannaf Ibn Abi Shayba 1:1377

Ibn Idris narrated to us, from Ibn Jurayj, who said: I said to 'Ata', "What do you think of a man who performs ablution in that basin while uncovered?" He said, "There is no harm in it. Ibn Abbas has indeed made it [available], and he knew that the white and the black [people] perform ablution from it."