Ibn Qudāmah رحمه الله said:

“وإن أحرم مأموما، ثم نوى مفارقة الإمام، وإتمامها منفردا لعذر، جاز” “If he begins the prayer as a follower and then intends to separate from the imam and complete it individually due to an excuse, that is permissible.” He then explicitly includes among the legitimate excuses: “المشقة بتطويل الإمام، أو المرض، أو خشية غلبة النعاس، أو شيء يفسد صلاته، أو خوف فوات مال أو تلفه، أو فوت رفقته، وأشباه هذا” “Hardship caused by the imam lengthening the prayer, illness, fear of being overcome by sleep, something that may spoil his prayer, fear of losing property or its destruction, fear of missing his travelling companions, and similar matters.” Al-Mughnī (2/34). Shaykh ʿAbdul-ʿAzīz ibn Bāz رحمه الله was asked whether separation from the imam is permissible due to a genuine need. He replied: “يجوز إذا طول الإمام، يكون يشق على بعض المأمومين، يكون له حاجة أو عنده ضعف؛ لأن الرسول ﷺ ما أنكر عليه، بل أنكر على معاذ” “It is permissible when the imam lengthens the prayer and this becomes difficult for some of the followers, or the person has a need, or he has weakness; because the Messenger ﷺ did not condemn him. Rather, he condemned Muʿādh.” Source: https://binbaz.org.sa/fatwas/24166/%D9%85%D8%AA%D9%89-%D9%8A%D8%AC%D9%88%D8%B2-%D9%84%D9%84%D9%85%D8%A7%D9%85%D9%88%D9%85-%D8%A7%D9%84%D8%A7%D9%86%D9%81%D8%B1%D8%A7%D8%AF-%D8%B9%D9%86-%D8%A7%D9%84%D8%A7%D9%85%D8%A7%D9%85 Therefore, there is no contradiction between saying that the Sunnah is for the imam to lengthen the eclipse prayer and recognising that a particular individual may have a genuine excuse. The imam establishes the Sunnah, while the person who genuinely cannot continue has a legislated concession. This illustrates the benefit of approaching these matters upon knowledge: “العلم نور” “Knowledge is light.” When matters are approached upon knowledge, apparent difficulties are resolved through the guidance of the Sharīʿah itself. Otherwise, a person may attempt to “correct” an established Sunnah while being unaware that the Sunnah itself has already provided the appropriate solution. ━━━━━━━━━━━━━━━━━━ The Established Description of the Eclipse Prayer The strongest and most widespread description transmitted concerning the eclipse prayer is: Two rakʿahs, with two rukūʿs in each rakʿah. The narration of ʿĀʾishah رضي الله عنها describes the Prophet ﷺ performing two standings and two rukūʿs (bowings) in the first rakʿah, followed by the corresponding manner in the second. Ṣaḥīḥ al-Bukhārī, no. 1046; Ṣaḥīḥ Muslim, no. 901. Ibn Qudāmah رحمه الله describes the same form in detail in Al-Mughnī (2/143). Thus, the well-established description contains four rukūʿs altogether. ━━━━━━━━━━━━━━━━━━ If a Latecomer Misses an Entire Rakʿah If the latecomer completely misses the first rakʿah and catches the second from its beginning, the matter is straightforward. He follows the imam and, after the imam gives salām, performs the rakʿah which he missed according to the description of the eclipse prayer. An-Nawawī رحمه الله said: “وإن أدركه في الركوع الأول من الركعة الثانية فقد أدرك الركعة، فإذا سلم الإمام قام فصلى ركعة أخرى بركوعين وقيامين كما يأتي بها الإمام، وهذا لا خلاف فيه” “If he catches the imam in the first rukūʿ of the second rakʿah, he has caught that rakʿah. When the imam gives salām, he stands and performs another rakʿah with two rukūʿs and two standings in the manner performed by the imam, and there is no disagreement concerning this.” Al-Majmūʿ Sharḥ al-Muhadhdhab (5/61). The more difficult question is: What if he joins the imam after the first rukūʿ but catches the second rukūʿ of the same rakʿah? Here there is a genuine disagreement among the scholars. ━━━━━━━━━━━━━━━━━━ The First Position: The Rakʿah Is Only Caught by Catching the First Rukūʿ This is the well-known position among the Shāfiʿīs and one of the recognised positions among the Ḥanbalīs, and it was preferred by a number of later scholars. An-Nawawī رحمه الله said: “ولو أدركه في الركوع الثاني من إحدى الركعتين فالمذهب الصحيح الذي نص عليه الشافعي في البويطي واتفق الأصحاب على تصحيحه، وقطع به كثيرون منهم أو أكثرهم أنه لا يكون مدركا لشيء من الركعة” “If he catches the imam in the second rukūʿ of either rakʿah, then according to the correct position of the madhhab, which al-Shāfiʿī explicitly stated in al-Buwayṭī and which the scholars of the school agreed to authenticate, he is not considered to have caught any part of that rakʿah.” Al-Majmūʿ Sharḥ al-Muhadhdhab (5/61). Shaykh Ibn ʿUthaymīn رحمه الله likewise explained: “واعلموا أن الركوع الثاني من كل ركعة ليس بواجب، بل هو سنة، والركوع الأول هو الواجب وهو الركن، ولهذا قلنا إن الركعة لا تدرك إلا بإدراك الركوع الأول؛ لأنه هو الركن، أما الثاني فإنه تطوع” “Know that the second rukūʿ of each rakʿah is not obligatory; rather, it is Sunnah. The first rukūʿ is the obligatory one and is the pillar. This is why we say that the rakʿah is not caught except by catching the first rukūʿ, because it is the pillar, whereas the second is voluntary.” Source: Al-Liqāʾ al-Shahrī (38/17). According to this analysis, the latecomer is not inserting an isolated rukūʿ into an already completed rakʿah. Rather, because the first rukūʿ is regarded as the essential rukūʿ by which the rakʿah is caught, the entire rakʿah is considered missed if that first rukūʿ was missed. ━━━━━━━━━━━━━━━━━━ The Second Position: The Rakʿah Is Caught by the Second Rukūʿ There is, however, another strong and well-founded position: the rakʿah is caught by catching the second rukūʿ. This is the established position of the Mālikī school, and it was also recognised as a valid position within the Ḥanbalī school. The Mālikī Position Ad-Dusūqī رحمه الله said: “وتدرك الركعة مع الإمام من كل ركعة بالركوع الثاني لأنه الفرض كالفاتحة قبله، وأما الركوع الأول فسنة” “The rakʿah with the imam is caught in each rakʿah by catching the second rukūʿ, because it is the obligatory rukūʿ, just as al-Fātiḥah preceding it is obligatory. As for the first rukūʿ, it is Sunnah.” Ḥāshiyat al-Dusūqī ʿalā al-Sharḥ al-Kabīr (1/404). He then explicitly states: “فمن أدرك مع الإمام الركوع الثاني من الأولى لم يقض شيئا” “Whoever catches the second rukūʿ of the first rakʿah with the imam does not make anything up.” Ḥāshiyat al-Dusūqī ʿalā al-Sharḥ al-Kabīr (1/404). This is not merely a later isolated interpretation. It represents the recognised Mālikī understanding of the structure of the eclipse rakʿah. According to their analysis, the second rukūʿ occupies the normal structural position of rukūʿ in a rakʿah: it follows the final recitation and is followed by the movement towards sujūd. The first rukūʿ is the additional rukūʿ particular to Ṣalāt al-Kusūf. Therefore, according to this position, a person who catches the second rukūʿ has caught the essential rukūʿ and consequently has caught the rakʿah. ━━━━━━━━━━━━━━━━━━ This Position Is Also Recognised Among the Ḥanbalīs The significance of this view becomes greater when we see that it is not restricted to the Mālikī school. Ibn Mufliḥ رحمه الله said: “والركوع الثاني سنة، وتدرك به الركعة في أحد الوجهين” “The second rukūʿ is Sunnah, and according to one of the two positions the rakʿah is caught by it.” Al-Furūʿ (2/140–141). He then records that the two positions were left open in al-Mughnī and ash-Sharḥ, and that the view that the rakʿah is caught by the second rukūʿ was given precedence in al-Riʿāyatayn. This is important. It means that the position was not merely tolerated as an external Mālikī opinion. It existed as one of the recognised positions within the Ḥanbalī school itself. Ibn Qudāmah رحمه الله also mentioned the possibility that the second rukūʿ is sufficient for the latecomer, reasoning that Ṣalāt al-Kusūf may validly be performed with one rukūʿ, and therefore the rukūʿ caught by the latecomer may suffice him. Al-Mughnī, discussion concerning the latecomer in Ṣalāt al-Kusūf. The fact that major Ḥanbalī jurists preserved this as a recognised possibility, and that some works gave it precedence, shows that it is a serious juristic position and not an anomalous one. ━━━━━━━━━━━━━━━━━━