764 - It was narrated that Marwan ibn al-Hakam said: Zayd ibn Thabit said to me: Why do you recite short surahs in Maghrib when I heard the Prophet (blessings and peace of Allah be upon him) reciting the longer of the two long surahs?.

Commentary : May Allah be pleased with the companions of the Messenger of Allah (blessings and peace of Allah be upon him), for they were very keen to find out about the sunnah of the Prophet (blessings and peace of Allah be upon him), and to enjoin others to adhere to it and forbid them to go against it.
This hadith tells us that the Sahabi Zayd ibn Thabit (may Allah be pleased with him)  said to Marwan ibn al-Hakam one day, rebuking him: Why do you recite short surahs in Maghrib – referring to the short surahs of al-Mufassal, from the beginning of Surat al-Bayyinah to the end of the Qur’an – when I heard the Prophet (blessings and peace of Allah be upon him) reciting the longer of the two long surahs? What is meant by the two long surahs is al-A‘raf and al-An‘am; the longer of the two is al-A‘raf, so it is as if what he meant here was Surat al-A‘raf.
It was narrated that the Prophet (blessings and peace of Allah be upon him) recited Surat al-Mursalat in Maghrib, as it says in the hadith narrated in Sahih al-Bukhari from Umm al-Fadl Lubabah bint al-Harith (may Allah be pleased with her); he also recited Surat al-Tur [in Maghrib], as it says in a hadith also narrated by al-Bukhari, from Jubayr ibn Mut‘im (may Allah be pleased with him). All of this indicates that the Prophet (blessings and peace of Allah be upon him) would sometimes vary the length of his standing [in prayer] according to circumstances. The hadith under discussion here indicates that this happened sometimes, although in most cases his practice was not to make the recitation in Maghrib lengthy.
This hadith highlights the practice of the Prophet (blessings and peace of Allah be upon him) with regard to recitation in Maghrib prayer..