Abu Hurairah (May Allah be pleased with him) reported: The Messenger of Allah (PBUH) said, "Allah, the Exalted, has teams of angels who go about on the roads seeking those who remember Allah. When they find some people remembering Allah they call to one another and say, `Come to what you are looking for;' and they surround them with their wings till the space between them and the lowest sky is fully covered. Allah, the Exalted and Glorious, asks them (although He is best informed about every thing): `What are my slave saying?' They say: `They are glorifying Your Tasbih, Tahmid, Takbir, Tamjid, (i.e., they were declaring Your Perfectness, praising, remembering the Greatness and Majesty of Allah).' He asks: `Have they seen Me?' They reply, `No, indeed, they have not seen You.' He asks: `How would they act if they were to see Me?' Thereupon they reply: `If they were to see You, they would engage more earnestly in worshipping and glorifying You and would extol You more.' He would say: `What do they beg of Me?' They say, `They beg You for Your Jannah.' Allah says, `Have they seen My Jannah?' They say, `No, our Rubb.' He says: `How would they act if they were to see My Jannah?' They reply, `Were they to see it, they would more intensely eager for it.' They (the angels) say, `They seek Your Protection.' He asks, `Against what do they seek My Protection?' They (the angels) say, `Our Rubb, from the fire of Hell.' (He, the Rubb) says, `Have they seen the fire of Hell?' They say, `No. By Your Honour, they have not seen it.' He says: `How would they act if they were to see My Fire?' They say: `If they were to see it, they would more earnest in being away from it and fearing it. They beg of Your forgiveness.' He says: `I call you to witness that I hereby grant pardon to them and confer upon them what they ask for; and grant them protection against what they seek protection from.' One of the angels says: `Our Rubb, there is amongst them such and such slave who does not belong to the assembly of those who are participating in Your remembrance. He passed by them and sat down with them.' He says: `I also grant him pardon because they are the people by virtue of whom their associates will not be unfortunate'.''
[Al-Bukhari and Muslim].

(The narration in Muslim is also the same with minor changes in wordings).

Commentary: What kind of circles and gatherings of remembrance of Allah are referred to here? Obviously not those in which Allah is remembered in the ways invented by the participants themselves, i.e., repetition of the slogans "Allah-Hu'', "Haq-Allah'', etc.,which have not been mentioned in any Hadith. The repetition of any specific word, in a specific manner and in a peculiar surrounding (such as by putting the lights off) - this manner of conducting the remembrance of Allah is also not evident from the practice of the Prophet (PBUH) and his Companions. The circles and gatherings mentioned in this Hadith are those in which, the Prophet's Sunnah is fully observed. The words such as Subhan-Allah, Al-hamdu lillah, La ilaha illallah, Allahu Akbar etc., are recited and Praise and Glorification of Allah are done after Salat. The groups are quietly engaged in the remembrance of Allah, and those who attend the sermons and speeches delivered in mosques on Friday also come in this category of meetings and gatherings as these are ordained in Islam. This Hadith also highlights the distinction of Muslims who are engaged in the remembrance of Allah and the Du`a they recite on the suggested times and occasions.