Abd al-Rahman bin Abza (may Allah be pleased with him) said: I offered the funeral prayer with Umar (may Allah be pleased with him) over Zaynab (may Allah be pleased with her), the wife of the Prophet (peace and blessings be upon him), and he said four takbirs. Then he sent word to the wives of the Prophet (peace and blessings be upon him) asking who should place her in her grave, and Umar (may Allah be pleased with him) would have liked to place her in her grave himself. So they sent word to Umar (may Allah be pleased with him): the one who used to see her during her lifetime should place her in the grave. Umar (may Allah be pleased with him) said: They have spoken the truth.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الجنائز / 6949