What is the ruling on the Eclipse Prayer if the Imam does not recite Al-Fatihah after rising from bowing in the first رکعة, or if he says "Allahu Akbar" instead of "Sami'a Allahu liman Hamidah" when rising from bowing in the Eclipse Prayer? And is there any obligation upon the congregants in these two cases?

The eclipse prayer is valid if the recitation after the first bowing (ruku') of each unit (rak'ah) is a sunnah (recommended act), and saying "Sami'a Allahu liman hamidah" (Allah hears those who praise Him) upon rising from bowing is either obligatory or a sunnah. It is sunnah for the Imam to perform the prostration of forgetfulness (sujud al-sahw), and if he does not prostrate, there is no blame on the followers (ma'mumeen).

The basic form of the eclipse prayer is two units (rak'ahs), with two standings (qiyam), two recitations (qira'ah), two bowings (ruku'), and two prostrations (sujud) in each rak'ah. The first rak'ah is performed with takbirat al-ihram (opening takbir), istiftah (opening supplication), isti'adhah (seeking refuge), recitation of Al-Fatiha and Surah Al-Baqarah (or an equivalent length). Then one bows (ruk'u) and prolongs the tasbeeh (glorification). Then one rises and says "Sami'a Allahu liman hamidah, Rabbana wa lakal hamd" (Allah hears those who praise Him, Our Lord, and to You be all praise). Then one recites Al-Fatiha and Al 'Imran (or an equivalent length). Then one bows (ruk'u) for about two-thirds the length of the first bowing. Then one rises and performs two long prostrations. Then one stands for the second rak'ah, recites Surah An-Nisa, then bows and glorifies for about two-thirds the length of the second tasbeeh. Then one rises and recites Al-Fatiha and Al-Ma'idah, then bows and prolongs it, then rises and performs two long prostrations.

If one performs it as two rak'ahs like a voluntary prayer, it is valid, and likewise if one performs it with six bowings. The evidence for this is what 'Aisha (may Allah be pleased with her) narrated: that the Prophet (peace and blessings be upon him) prayed the eclipse prayer with two standings, two bowings, and two prostrations in each rak'ah.