Shu'ayth said to his father Mutayr: O my respected father! You told me that Dhul-Yadayn (may Allah be pleased with him) met you at Dhu Khashab and informed you that the Messenger of Allah (peace and blessings be upon him) led them in one of the prayers after the sun has passed its zenith, and it was the Asr prayer, and he (peace and blessings be upon him) gave the salam after two rak'ahs. Then the Messenger of Allah (peace and blessings be upon him) stood up, and Abu Bakr and Umar (may Allah be pleased with them both) also set off behind him. The hasty people went out, and Dhul-Yadayn, Abu Bakr and Umar (may Allah be pleased with them) caught up with the Messenger of Allah (peace and blessings be upon him). Dhul-Yadayn (may Allah be pleased with him) said: O Messenger of Allah! Has the prayer been shortened, or have you forgotten? The Messenger of Allah (peace and blessings be upon him) said: "Neither has the prayer been shortened, nor have I forgotten." Then the Messenger of Allah (peace and blessings be upon him) turned to Abu Bakr and Umar (may Allah be pleased with them both) and said: "What is Dhul-Yadayn saying?" They both said: O Messenger of Allah! He is telling the truth. He (peace and blessings be upon him) turned back, and the people had dispersed; the Messenger of Allah (peace and blessings be upon him) led two rak'ahs and then performed the two prostrations of forgetfulness.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 3928