Abu Amr al-Shaybani said that Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) used to permit a man whose wife died before consummation to marry her mother. Then Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) came to Madinah and met Sayyiduna Umar (may Allah be pleased with him), and he retracted (that view).
Hadith Referenceالسنن الكبرى للبيهقي / كتاب النكاح / 13906