The Jum`ah Prayer, in fact, enjoys particular privileges in Islam to the extent that a Surah of the Glorious Qur’an is named “Al-Jum`ah”. Muslims are commanded by Allah to forsake all worldly business at the time of the Jum`ah and attend the Salah in the mosque. In this context, Allah Most High says, “O ye who believe! When the call is heard for the prayer of the day of congregation (Friday), haste unto remembrance of Allah and leave your trading. That is better for you if ye did but know. And when the prayer is ended, then disperse in the land and seek of Allah’s bounty, and remember Allah much, that ye may be successful. But when they spy some merchandise or pastime they break away to it and leave thee standing. Say: That which Allah hath is better than pastime and than merchandise, and Allah is the best of providers.” (Al-Jum`ah: 9-11)
Keeping the above mentioned in mind, the Muslim should attend the Jum`ah and attentively listen to the khutbah (sermon). Likewise, he should refrain from anything that interrupts the imam or makes noise in the mosque.
Sheikh Ahmad Kutty, a senior lecturer and Islamic scholar at the Islamic Institute of Toronto, Ontario, Canada, states: “It should be common knowledge for every Muslim that during Friday Prayer we must observe silence; we are not allowed to disrupt the khutbah or Prayer by engaging in any activity. The Prophet (peace and blessings be upon him) is reported to have said: “Whoever indulges in idle talks or deeds during the khutbah, his Jum`ah is invalid.”
Therefore, the use of cell phones during the khutbah by the imam or the followers is totally unacceptable. It is a sign of disrespect for this important symbol of Islam. The Qur’an says: “Whoever reveres the symbols of Allah, he does so simply because of the piety in his heart.” (Al-Hajj: 32)”