Those who permitted sleeping on Friday

Al-Jurayri said: Abu al-Ala' used to fall asleep while sitting during Jumu'ah.

Malik bin Dinar said: Abu al-Aliyah and Khilas bin Amr used to sleep a long sleep during Jumu'ah, then they would stand up and pray.

Nafi' said: Sayyiduna Ibn Umar (may Allah be pleased with them both) used to sit in ihtiba' (with his knees drawn up and wrapped) during Jumu'ah while the imam was delivering the sermon; and if the sermon became long, he would place his head in my lap.