Musnad Ahmad 27:1910

'Abd al-Razzaq narrated to us, from Ibn Jurayj, and Ibn Bakr said: Ibn Jurayj informed us, Ibn Shihab informed me, from 'Abd Allah ibn 'Abd Allah, from 'Abd Allah ibn 'Umar, that the Messenger of Allah (may Allah bless him and grant him peace) said, while he was standing on the pulpit: "Whoever among you comes to the Friday [prayer], let him perform ghusl."