Ruling on inviting people to fast together on a particular day and offer supplication (du`a) on that day
Question

What is the ruling on inviting people to fast together on a particular day, and all recite a specific supplication (specifying what is to be said in that supplication), and at a specific time (such as saying: “We invite everyone at such and such an hour Makkah time) to support our Muslim brothers in Palestine, or some other Muslim country; please share and circulate this invitation, by text or Internet”)?
Praise be to Allah.The Muslims faced crises at the time of the Prophet (blessings and peace of Allah be upon him) and his companions and those who came after them, and they did not call on one another to fast on a specific day and offer specific supplications at a specific time. Thus it is known that doing this is an innovation (bid‘ah); if it was something good, then the Prophet (blessings and peace of Allah be upon him) and his companions would have done it.
Shaykh Ibn ‘Uthaymin (may Allah have mercy on him) said:
What is the ruling on fasting together and agreeing to meet for iftar, whether that is during Ramadan or on Mondays and Thursdays?
He replied:
No, the most serious issue is agreeing to fast on a particular day. We think that this is something that the Sahabah never did; they never agreed or promised one another that they would fast on Mondays and Thursdays, and so on, and there is the fear that the matter may develop into something more serious than that, in which case we would be imitating the Sufis who agree to recite a specific dhikr, which they get together and recite in unison. Hence if someone says to his friends: ‘Whoever fasts tomorrow, iftar will be at So-and-so’s house,’ there is nothing wrong with that, but agreeing and promising one another to fast on a specific day, this is not the practice of the Sahabah. Moreover, the fact that a person gets accustomed to not fasting unless someone else fasts with him is problematic. The individual should fast on his own initiative, regardless of whether someone else is fasting with him or not. This is the way of the righteous early generations."(Liqa’ al-Bab al-Maftuh  174/24).
He was also asked about some people who get together in the blessed month of Ramadan to recite some adhkar and du`as that are narrated in the Sunnah; they do that before the time of iftar and they recite together in unison. Is it permissible for us to do that?
He (may Allah have mercy on him) replied:
When the Messenger of Allah (blessings and peace of Allah be upon him) gave a khutbah, his eyes turned red, he raised his voice and sounded angry, and he said: “To proceed: the best of speech is the Book of Allah and the best of guidance is the guidance of Muhammad; the worst of matters are those that are newly introduced into the religion. Every innovation is a going astray, and every going astray leads to the Fire.” When he (blessings and peace of Allah be upon him) broke his fast, he did not call people together so that they could remember Allah, may He be glorified and exalted, or call upon Allah, may He be glorified and exalted, in a loud voice and reciting in unison with others. Rather each person broke his fast with his family, and each person offered supplication by himself, speaking quietly, between him and his Lord. As this habit that is referred to by the questioner was not known at the time of the Prophet (blessings and peace of Allah be upon him), then we know that it comes under the heading of innovations which the Messenger of Allah (blessings and peace of Allah be upon him) warned us against, and explained that every innovation is a going astray, and every going astray leads to the Fire."(Fatawa Nur ‘ala al-Darb  212/6-7).
Shaykh ‘Abd al-Rahman al-Suhaym was asked:
In the past, we always received messages via email asking us to fast on a specific day and to pray qiyam on that day in support of our brothers in Palestine, by way of encouraging us to offer supplication and to exhort one another to hold fast to the truth.
Is it an innovation (bid‘ah), for a group of us to agree that each of us will pray qiyam at home on a specific night, in which we will offer supplication, reciting du`as from the Quran and Sunnah?
He replied:
As for doing righteous deeds for the sake of supporting our brothers in Palestine, I think that this idea is an innovation that originally came from the Christian countries.
Seventy of the reciters of Quran among the companions of the Prophet (blessings and peace of Allah be upon him) were killed, yet despite that there is nothing to suggest that he (blessings and peace of Allah be upon him) fasted or prayed (salah) for their sake. Rather he offered supplication (du`a), calling upon Allah, may He be glorified and exalted, as is narrated in al-Sahihayn.
Similarly, when he sent the army on the day of Mu’tah, then became aware that some of his companions had been killed, there is no report to suggest that he did any such actions.
Rather his practice was to offer supplication (du`a) and strive hard in doing so.
He (blessings and peace of Allah be upon him) strove hard in offering supplication on the day of Badr.
He also offered supplication from the minbar on Fridays, and this is something that khatibs need to be reminded of.
As for agreeing to pray qiyam on a specific night, this is something for which there is no basis in Islamic teachings, unless someone gets up to pray qiyam and others follow his lead and get up to pray qiyam too, without any prior promise or agreement.
The Prophet’s cousin Ibn ‘Abbas (may Allah be pleased with him) stood behind him (blessings and peace of Allah be upon him) and joined him in prayer [at night], as did Hudhayfah (may Allah be pleased with him) on one occasion.
And on one occasion, Ibn Mas‘ud (may Allah be pleased with him) stood behind him and joined him (blessings and peace of Allah be upon him) in praying qiyam.
But all of that happened without any prior agreement or promise.
Similar to that is if a man gets up to pray qiyam, and one of his children gets up and prays with him, or if a righteous man stays overnight in someone’s house and gets up to pray qiyam; in that case it is permissible to join him in prayer.
The Prophet (blessings and peace of Allah be upon him) forbade singling out the night before Friday for praying qiyam, without praying qiyam on other nights, lest anyone think that that night has any particular virtue that other nights do not have.
I do not think there is any need to make an agreement to pray qiyam on a specific night; rather each of you can encourage and exhort others to pray qiyam and strive hard in offering supplication for the weak and oppressed throughout the world, east and west."(Mishkat website).
What appears to us to be the case is that this invitation is not Islamically acceptable, and it is not appropriate to take part in it or invite others to do so.
What is required of the Muslim is to offer supplication and pray to Allah for his Muslim brothers everywhere, without allocating a specific time for that or fasting for that purpose.
We ask Allah to save the weak and oppressed believers, and to destroy the oppressors and aggressors.
And Allah knows best.