Musnad Ahmad

It is narrated from Hazrat Abu Hurairah (may Allah be pleased with him) that once the Holy Prophet (peace and blessings be upon him) led one of the two afternoon prayers, either Zuhr or Asr, most probably, and after leading only two rak'ahs, he said salam and finished the prayer. He then came to the pillar in the mosque which was broad, and with his hand made a gesture as if he was angry. The hasty people began to leave the mosque and started saying that the number of rak'ahs in the prayer had been reduced. Among the people present at that time were Hazrat Abu Bakr Siddiq (may Allah be pleased with him) and Hazrat Umar Farooq (may Allah be pleased with him), but they felt awe in speaking to the Holy Prophet (peace and blessings be upon him) about this matter. At this, Dhul-Yadain said: "O Messenger of Allah! Did you forget or has the number of rak'ahs in the prayer been reduced?" The Holy Prophet (peace and blessings be upon him) said: "I have neither forgotten nor has the number of rak'ahs been reduced." Dhul-Yadain said: "You have only performed two rak'ahs." The Prophet (peace and blessings be upon him) looked questioningly towards the companions (may Allah be pleased with them), as if to ask whether it was as Dhul-Yadain was saying. The companions (may Allah be pleased with them) confirmed it. Upon this, the Holy Prophet (peace and blessings be upon him) stood up and performed two more rak'ahs, then said salam, said "Allahu Akbar," and performed a prostration like that of prayer or even longer, then raised his head and said takbeer and sat down, then again said takbeer and performed a second prostration.