Dhikr Aloud after Salat is the Sunnah
Question: What is the ruling on raising the voice when seeking forgiveness (saying “astaghfirullaah” three times) and utterening dhikr after prayer, bearing in mind that this disturbs the others, since they find difficulty in maintaining a sense of humility in Tasbih and remembrance? Also, it is difficult for those who are completing their prayers to do so with humility and contemplation.
Shaikh al-‘Uthaimeen (rahimahullaah) answered:
The Sunnah is to say it aloud, as the Prophet (salallaahu ‘alaihi wa sallam) used to say it aloud. Ibn ‘Abbas (radiallaahu ‘anhumma) said: They used to raise their voices when making dhikr after finishing the prayer in the time of the Prophet (salallaahu ‘alaihi wa sallam).
And if all of the people raise their voices, they will not disturb each other. But they will disturb each other if some of them say it aloud and others say it quietly. There is no doubt that it will disturb the one who says it quietly, but if he were to raise his voice like them, there would be no disturbance. As for those who are making up what they missed, they have brought it upon themselves; if they had wished, they could have come early and it would not have disturbed them.
And as I said, if all of the voices were mixed together, there would be no disturbance, even for those who are making up their prayers, just as you see now on Fridays; the people all recite the Noble Qur`an and they raise their voices but, in spite of this, the worshipper comes and prays and he does not experience any disturbance.
Ibn Baaz (rahimahullaah) said:
It has been authentically reported in the Sahihain (Two Sahihs) on the authority of Ibn ‘Abbaas (radiallaahu ‘anhumma) that in the time of the Messenger of Allaah (salallaahu ‘alaihi wa sallam), it was the practice to raise the voice when making dhikr after the obligatory prayers; he said: I used to know if they had finished (praying) when I heard it. 
This authentic hadith and others which carry the same meaning, such as the Hadith of Ibn az-Zubair, Al-Mughirah bin Shu’bah and others all prove the lawfulness of raising the voice when making dhikr after the people have finished the obligatory prayers, so that the people at the door of the mosque or those near to it will know that the prayer is over.
But whoever finds people praying what they have missed of the obligatory prayer near to him, it is better for him to lower his voice a little so that he does not disturb them, according to other evidences. And in raising the voice when making dhikr after the obligatory prayers, there are many benefits, including demonstrating the [saying] of Allaah’s praises for the blessing He has conferred on them through their performance of this great obligatory prayer, and it teaches the ignorant and reminds those who forget; and if it were not for this, the Sunnah would remain unknown to many people. And Allaah is the Granter of success.
 Al-Bukhari no. 841; Muslim no. 583.
Source: Fatawa Islamiya, Volume 2
Allaamah Ubayd al-Jaabiree said, “Hajr Wiqaaee (الهجر الوقائي – self-protective boycotting) is when you, by your own self, boycott an innovator. You know that he is an enemy to the Sunnah and its people. And you know that his usool (foundations) are not upon the Sunnah. Then you may boycott him on your own – you do not visit him or invite him to visit you, you do not sit where he sits, you may do this.”
Following is modified from the comments by Br. Abul Abbas Moosaa Richardson:-
Ibn ‘Abdil-Barr declared a scholarly consensus (ijmaa’) about this type of boycotting(i.e. Hajrul-wiqaa’ee):”And the scholars have unanimously agreed that it is not permissible for a Muslim to boycott his brother for more than three days unless he fears that by speaking to him or keeping ties with him that he may corrupt his Religion, or he fears that he may cause the sprouting of some harmful affairs within himself, things that harm his religious or worldly affairs. If this is the case, then there is a concession for him to stay away from him and keep distant. Quite often a good breaking of ties is better than a harmful relationship!” [at-Tamheed, 15/79, 2nd printing of the al-Faarooq al-Hadeethah printing]
So beware of those who blame the Muslims for protecting themselves from the dangers of those who spread doubts and confusion. For their refusal to sit with such people or listen to them is a proof that they love Allaah’s Guidance, they do not see it as being cheap, and they take the necessary measures to protect it.
Know the reality of those who limit boycotting to Hajr Ta’deebee only (الهجر التأديبي – Disciplinary Boycotting), and then criticize those who practice Hajr al-wiqaa’ee, blaming them for boycotting in a way that does not bring a positive change to the boycotted individual, which is not even the intent behind hajr wiqaa’ee! They seek to divert the people from the safe, clear way of the Salaf, the way of safety and security, and lead them to the muddy, confusing paths of misguidance and innovation. They blame the Muslims for what is unanimously agreed upon by the scholars (as shown above) and what was even mentioned by the Prophet (sallallaahu ‘alayhe wa sallam):”Verily the most evil people are those who the people abandon to protect themselves from their obscene behavior.” (Saheeh al-Bukhaaree #6054)
Note: This does not condone the mistaken practice of those with knowledge and understanding of the Religion boycotting those who are ignorant and merely mistaken. Such people are to be advised and taught, with leniency and patience.