Musannaf Ibn Abi Shayba 3:3012

Sufyan ibn 'Uyaynah narrated to us, from 'Abd al-Karim, from Mujahid or someone else, who said: Whoever sells something after the sun has passed its zenith on the day of Jumu'ah, his sale is rejected, for Allah has forbidden selling when the call is made for prayer on the day of Jumu'ah. Sufyan was in doubt [regarding the chain of narration].