(a) Sayyiduna Abu Sa'id al-Khudri (may Allah be pleased with him) narrates: In the Zuhr and Asr prayers we used to estimate from the standing of the Messenger of Allah (peace and blessings be upon him) how much he had recited in the two rak'ahs. We estimated that in the first two rak'ahs of Zuhr he stood for as long as it takes to recite Surah al-Sajdah, and in the last two rak'ahs his standing was half that of the first two. Then we estimated his standing in the first two rak'ahs of Asr, and it was equal to the recitation of the last two rak'ahs of Zuhr, and in the last two rak'ahs of Asr it was half that of the first two rak'ahs of Asr.
(b) In the hadith of Musaddad it is: equal to the recitation of thirty verses.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 2477
Hadith Gradingمحدثین:صحيح
Hadith Takhrij«صحيح۔ اخرجه ابن ابي شيبة 7755، مسلم»
It is narrated from Sayyiduna Abu Sa'id al-Khudri (may Allah be pleased with him) that he (peace and blessings be upon him) used to recite in each of the first two rak'ahs of Zuhr about the measure of thirty verses, and in the last two rak'ahs of Zuhr the measure of fifteen verses, or half of that; and in each of the first two rak'ahs of Asr the measure of fifteen verses, and in the last two rak'ahs half of that.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 2478
Qays bin al-Harith said: Abu Abdullah al-Sunabihi told me that he came to Madinah during the caliphate of Sayyiduna Abu Bakr al-Siddiq (may Allah be pleased with him). He prayed the Maghrib prayer behind Sayyiduna Abu Bakr al-Siddiq (may Allah be pleased with him). He (may Allah be pleased with him) recited in the first two rak'ahs Surah al-Fatihah and one short surah each, then he stood up for the third rak'ah. I drew near to him until my clothes almost touched his clothes. I heard him recite Surah al-Fatihah and this verse: "Our Lord, do not let our hearts deviate after You have guided us, and grant us mercy from Yourself. Indeed, You are the Bestower." [Surah Al Imran: 8]
Abu Sa'id added in his narration that Imam al-Shafi'i (may Allah have mercy on him) said: Sufyan bin Uyaynah said that when Umar bin Abd al-Aziz (may Allah have mercy on him) heard this narration, he said: "Before hearing it, this was not my practice; now that I have heard it, I will act upon it."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 2479
Hadith Gradingمحدثین:صحيح
Hadith Takhrij«صحيح۔ اخرجه مالك وعنه الشافعي في الام 7/ 207۔ 228»
It is narrated from Nafi' that when Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) prayed alone, he would recite in all four rak'ahs, reciting Surah al-Fatihah and another surah in every rak'ah, and sometimes in a single rak'ah of an obligatory prayer he would recite two or three surahs. Likewise, in the two rak'ahs of Maghrib he would recite Surah al-Fatihah and one surah each.
Imam al-Shafi'i (may Allah have mercy on him) did not mention Maghrib.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 2480