Sahih Bukhari, Chapter: Friday Prayer

On a rainy day Ibn Abbas said to his Muadh-dhin, "After saying, 'Ash-hadu anna Muhammadan Rasulullah' (I testify that Muhammad is Allah's Apostle), do not say 'Haiya 'Alas-Salat' (come for the prayer) but say 'Pray in your houses'." (The man did so). But the people disliked it. Ibn Abbas said, "It was done by one who was much better than I (i.e. the Prophet (p.b.u.h) ). No doubt, the Jumua prayer is compulsory but I dislike to put you to task by bringing you out walking in mud and slush."