Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) said that the Prophet (peace and blessings be upon him) said: "May Allah have mercy on a person who offers four rak'ahs before Asr."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 4485
This is another chain of the previous hadith: Muhammad bin Mihran al-Qurashi narrates from his grandfather Abu al-Muthanna, from Ibn Umar (may Allah be pleased with them both), with the same wording.
This is the correct version. He is Abu Ibrahim Muhammad bin Ibrahim bin Muslim bin Mihran al-Qurashi, who heard from his grandfather Muslim bin Mihran al-Qurashi. He is also called Muhammad bin al-Muthanna, that is, Ibn Abi al-Muthanna, because Muslim's kunyah was Abu al-Muthanna; al-Bukhari mentioned this in al-Tarikh.
The statement of the one who said 'from his father' in the first chain is, in my view, a mistake, and Allah knows best. A group narrated it from Abu Dawud without mentioning his father, among them Salamah bin Shabib and others.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 4486
Asim bin Damrah (may Allah have mercy on him) said: We asked Sayyiduna Ali (may Allah be pleased with him) about the prayer of the Prophet (peace and blessings be upon him), and Sayyiduna Ali (may Allah be pleased with him) described his (peace and blessings be upon him) prayer, mentioning in it four rak'ahs before Zuhr and two after it, and four rak'ahs before Asr.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 4487