Abu Dawud

575. Commentary:
➊ Although the Messenger of Allah (sallallahu alayhi wa sallam) was extremely humble, he was also exceedingly awe-inspiring and majestic. And the sole reason for this was the piety (taqwa) of Allah, the Exalted, and His fear (khashyah).
➋ Whoever has performed the prayer alone and then finds a congregation, he should join the imam and perform the prayer again.
➌ No matter which prayer it is, the apparent wording of the hadith indicates permission for this.
➍ It is understood from this that, due to a legal (shar‘i) reason, prayer can be performed after Fajr and ‘Asr.
➎ It is also indicated here that the prayer of a person performed alone is valid, even though performing it in congregation is necessary.
➏ It is also established that the first prayer will be obligatory (fard) and the second will be supererogatory (nafl).

859. Commentary:

➊ The Masjid Khaif is in Mina, and this incident took place during the Farewell Pilgrimage (Hajjat al-Wada‘). There is no possibility of it being abrogated.

➋ "He was trembling." There was a natural awe and majesty in the Messenger of Allah (sallallahu alayhi wa sallam). Whoever saw him for the first time, or saw him only occasionally, would become overawed. As for this individual, he had not only been summoned but was actually brought in, so in addition to being overawed, it was quite likely for him to be fearful as well.

➌ In this narration, it is explicitly stated regarding the Fajr prayer that if someone who prayed alone finds the congregation, he should pray again. Therefore, to leave aside this explicit narration and instead deduce from a general narration is contrary to fairness.

➍ "It will become a voluntary (nafl) prayer." Which one? There is a difference of opinion regarding this, and for this reason, the scholars have said: This is left to Allah; He makes obligatory (fard) whom He wills and voluntary whom He wills. However, it is apparent that the first prayer, when it was performed, was done with the intention of obligation (fard), so the second prayer should be considered voluntary (nafl). This position is supported by the light of the ahadith. And Allah knows best.

1:
Some people have restricted this to Zuhr and Isha, and they say that it is not permissible to perform supererogatory (nafl) prayers after Fajr and Asr, and if Maghrib is repeated, it will become even (shaf‘), but this is not correct because this ruling is general and includes all prayers.

Takhrij:
«أخرجه أبوداود، الصلاة، باب فيمن صلي في منزله ثم أدرك...، حديث:575، والترمذي، الصلاة، حديث:219، والنسائي، الإمامة، حديث:859، وابن حبان (الإحسان):3 /50، حديث:1563.»©

Explanation:
From this hadith, it is understood that if a person has already performed the prayer and then gets the opportunity to join the congregational prayer (jama‘ah), he should join the congregation, regardless of which prayer it is. This is the opinion of Imam Shafi‘i rahimahullah. In contrast, according to Imam Abu Hanifah rahimahullah, one may do so only in the Dhuhr and ‘Isha prayers, not in the others. However, since the evidence for repeating the prayer is this very hadith, then why should one not repeat the other prayers as well? Therefore, the position of Imam Shafi‘i rahimahullah is correct.

©

Hadith Narrator:
«حضرت یزید بن اسود رضی اللہ عنہ » His kunyah is Abu Jabir. He was from the Suwai‘ tribe of ‘Amir. His tribe had an alliance with the Quraysh. He is a well-known Companion (sahabi). He settled in Ta’if. Only this one hadith is narrated from him. His son Jabir rahimahullah narrated it from him.