Abd al-Rahman bin Abdullah bin Ka'b bin Malik narrates in this story that al-Bara' bin Ma'rur (may Allah be pleased with him) was the first person to face the Qiblah both when alive and when dead.
This is a good (jayyid) mursal report.
Al-Hasan (may Allah have mercy on him) says: Umar (may Allah be pleased with him) mentioned the Ka'bah and said: By Allah, these are only stones which Allah Almighty has set up as our Qiblah for our living, and we turn our dead towards it as well.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الجنائز / 6605