Using musical tunes as the ring tones for cell phones is an evil action and is haraam, because the Prophet (peace and blessings of Allaah be upon him) forbade all musical instruments. See the answer to question no. 47407.
The one who forgets to turn off his cell phone during the Friday khutbah has to turn it off if it rings, even if the ring tone is permissible, because leaving it disturbs the khateeb and other worshippers, and distracts them from the obligation of listening to the khateeb.
We hope that switching it off does not come under the heading of idle talk that is forbidden during the Friday khutbah, which is referred to in the question. This is mentioned in the words of the Prophet (peace and blessings of Allaah be upon him), “but whoever touches the pebbles has engaged in an idle action.” Narrated by Muslim (857).
The hadeeth applies to the one who fiddles with something that distracts him from listening to the khutbah, such as a cell phone, a carpet and so on.
Al-Haafiz Ibn Hajar, in Fath al-Baari, commentary on hadeeth no (934), narrated that the majority of scholars said that the one who needs to enjoin something good or forbid something bad at the time of the khutbah may do so by gesturing.
Al-Nawawi said in Sharh Saheeh Muslim:
This hadeeth indicates that all kinds of speech are haraam during the khutbah. … Rather the way to do it if one wants to tell someone else not to speak is by gesturing to him to be quiet, if he will understand it. End quote.
Based on this, then a slight movement that is done for a good reason is acceptable and is not idle action, and there is nothing wrong with doing it during the Friday khutbah.
The meaning of the Prophet’s words, “There is no Jumu’ah for him”, concerning the one who engages in idle action during the Friday khutbah, is that it will be recorded for him as Zuhr, and he will be deprived of the reward for Jumu’ah prayer.
It was narrated from ‘Abd-Allaah ibn ‘Amr ibn al-‘Aas (may Allaah be pleased with him) that the Prophet (peace and blessings of Allaah be upon him) said: “If a person engages in idle action or steps over people’s necks, it will be Zuhr for him.” Narrated by Abu Dawood (347); classed as hasan by al-Albaani in Saheeh Abi Dawood.
Al-Haafiz Ibn Hajar (may Allaah have mercy on him) said:
Al-Nadr ibn Shameel said: “you engaged in idle action” means: you lost something of your reward; and it was said: you invalidated the virtue of your Jumu’ah. And it was said: Your Jumu’ah became Zuhr.
I [Ibn Hajar] said: The comments of the scholars of [Arabic] language are close in meaning, and the latter view is supported by what Abu Dawood and Ibn Khuzaymah narrated from ‘Abd-Allaah ibn ‘Amr in a marfoo’ hadeeth: “If a person engages in idle action or steps over people’s necks, it will be Zuhr for him.” Ibn Wahb – one of the narrators – said: What it means is: His prayer is still valid but he is deprived of the virtue of Jumu’ah. End quote.
Fath al-Baari (2/414).
Badr al-Deen al-‘Ayni (may Allaah have mercy on him) said:
The words “it will be Zuhr for him” mean: his Jumu’ah will be Zuhr for him, in the sense that the virtue that he would have attained from Jumu’ah will not be attained, because he failed to fulfil the condition of this virtue. End quote.
Sharh Sunan Abi Dawood (2/169).
What those who come to Jumu’ah prayer should do is respect the symbols of Allaah, which includes keeping the physical faculties still and refraining from fidgeting, and keeping the tongue still and refraining from talking, otherwise he has sinned and his Jumu’ah has become Zuhr.
Shaykh Saalih al-Fawzaan (may Allaah preserve him) said:
Undoubtedly the Muslim is enjoined during the khutbah to listen and pay attention, and stop moving. He is enjoined to do two things:
1. Be silent and still, and refrain from moving or fidgeting.
2. He is enjoined to be quiet and refrain from speaking. It is haraam for him to speak whilst the imam is delivering the khutbah, and it is also haraam for him to move, fidget, touch the pebbles, draw lines on the ground, or anything else of that nature. End quote.
Al-Muntaqa min Fataawa al-Shaykh Saalih al-Fawzaan (5/71).