Majma al-Zawaid — Hadith 2401

It is reported concerning Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him): Once Jundub and Masruq (both of them are Tabi'un) caught one rak'ah; the narrator says: that is, they caught one rak'ah of the Maghrib prayer behind the imam. Jundub recited behind the imam, while Masruq did not recite. When the imam said the salam, the two of them stood up and began to make up the prayer they had missed. Masruq sat after the second rak'ah and also sat after the third rak'ah, whereas Jundub stood up after the second rak'ah and did not sit. When the two of them had completed the prayer, they discussed this matter, and they came to Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him). He said: Both of you have done right (the narrator is unsure; perhaps the words are: Both of you have done well), and do as Masruq does.
Al-Tabarani recorded it in al-Mu'jam al-Kabir with several chains, in one of which a narrator has dropped out; and in this chain there is Jabir al-Ju'fi, whom most scholars have declared weak.