And prayers and peace be upon our Prophet Muhammad and upon his family and all his Companions: He said (may Allah have mercy on him): "Chapter on the Virtue of Congregational Prayer"

The reader: In the name of Allah, the Most Gracious, the Most Merciful.
Praise be to Allah, Lord of the worlds, and may peace and blessings be upon our Prophet Muhammad, and upon his family and all his Companions:
He said (may Allah have mercy on him): "Chapter on the Virtue of Congregational Prayer:
It was narrated from Ibn 'Umar (may Allah be pleased with them both) that the Messenger of Allah (peace and blessings be upon him) said:

Prayer said in a congregation is twenty-seven degrees more excellent than prayer said by a single person.

صلاة الجماعة أفضل من صلاة الفذ بسبع وعشرين درجة

Sahih Muslim 650a

Agreed upon by al-Bukhari and Muslim.
And it was narrated from Abu Hurayrah (may Allah be pleased with him) that he said: The Messenger of Allah (peace and blessings be upon him) said:

A man's Salat in congregation is twenty-five times more rewarding than his Salat at home or in his shop, and that is because when he performs his Wudu' properly and proceeds towards the mosque with the purpose of performing Salat in congregation, he does not take a step without being raised a degree (in rank) for it and having a sin remitted for it, till he enters the mosque. When he is performing Salat, the angels continue to invoke Blessings of Allah on him as long as he is in his place of worship in a state of Wudu'. They say: 'O Allah! Have mercy on him! O Allah! Forgive him.' He is deemed to be engaged in Salat as long as he waits for it.

صلاة الرجل في جماعة تُضعَّف على صلاته في بيته وفي سوقه خمسًا وعشرين ضِعفًا، وذلك أنه إذا توضأ فأحسن الوضوء، ثم خرج إلى المسجد لا يخرجه إلا الصلاة، لم يخط خطوة إلا رُفعت له بها درجة، وحُطت عنه بها خطيئة، فإذا صلى لم تزل الملائكة تصلي عليه ما دام في مصلاه، ما لم يحدث، تقول : اللهم صل عليه، اللهم ارحمه، ولا يزال في صلاة ما انتظر الصلاة

Riyad as-Salihin 1065

Agreed upon by al-Bukhari and Muslim, and this is the wording of al-Bukhari".

The Shaykh :"Chapter on the Virtue of Congregational Prayer": By this, he (may Allah have mercy on him) intends to explain the virtue of praying with the congregation. The scholars have agreed that congregational prayer is among the best acts of worship and the greatest of obedience, but they differed on whether it is a recommended practice (sunnah), an obligation, or a condition for the validity of the prayer?
There are three opinions: The first opinion is that it is a recommended practice (sunnah); if a person performs it, he is rewarded for it, and if he leaves it, there is no sin upon him.
The second opinion is that it is obligatory; it is obligatory for a person to pray with the congregation, and if he does not do so, he is sinful, but his prayer is valid.
The third opinion is that the congregation is a condition for the validity of the prayer, and that if he does not pray with the congregation, his prayer is invalid and not accepted from him. This last opinion is the choice of Shaykh al-Islam Ibn Taymiyyah (may Allah have mercy on him), and it is a narration from Imam Ahmad: "That if a person prays alone without a legitimate religious excuse, his prayer is not accepted", like one who prays without ablution. They reasoned this by saying that congregational prayer is obligatory, and the rule is: "Whoever leaves an obligatory part of the prayer, his prayer is invalid".
But the stronger opinion is that it is obligatory; a person sins by leaving it, but if he prays alone, his prayer is accepted. So it is not a condition for the validity of the prayer. This is indicated by the hadith of Abdullah ibn 'Umar (may Allah be pleased with them both), that the Prophet (peace and blessings be upon him and his family) said: : The aspect of indication is that if the prayer of the one alone had no reward, the comparison would not be valid. But a person who does not pray with the congregation sins.
As for the hadith of Abu Hurayrah, the Prophet (peace and blessings be upon him and his family) clarified that congregational prayer is better than a man's prayer in his home and his market, being twenty-five times better than that. There is no contradiction between the two hadiths; rather, the additional amount is taken because the favor of Allah is vast. Then he clarified that, saying: meaning he perfected it, : The single step has two benefits: The first is that a degree is raised for him thereby.
And the second is that a sin is removed from him thereby.
So when he prays, meaning he entered the mosque and prayed: : This is a great reward and a great favor that a sane, believing man should not neglect. If it were said to you: If you sell your merchandise in your country, you sell it for one hundred, and if you sell it in another country that you reach by traveling to it, you sell it for one hundred and ten, you would travel to that place for the sake of ten percent, and the travel would not be burdensome for you. And many people, may Allah protect us from that, are deprived of the good. You find them close to the mosque, leaving this great favor and this great gain, one by twenty-seven, meaning multiples of multiples, and yet they do not go to the mosque (we ask Allah for well-being). And the profit of this world, despite its littleness, they strive for it and care for it, although it is transient. For everything in this world of pleasure is either removed from you or you are removed from it, inevitably. There is no permanent residence. The pleasure in this world either disappears or you disappear from it. And the pleasure of the Hereafter remains, and yet some people neglect it and do not care for it. And the favor of Allah (Glorified and Exalted is He) He gives to whom He wills. We ask Allah to help us in His remembrance, His gratitude, and the excellence of His worship.