Imam al-Shafi'i (may Allah have mercy on him) said: The dream of the prophets is revelation too, and the weakness in Sayyiduna Abu Bakr's (may Allah be pleased with him) drawing of the bucket means that his period of caliphate would be short and he would die soon. He would be occupied with fighting the apostates, and Sayyiduna Umar's (may Allah be pleased with him) period of caliphate would be long.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب قتال أهل البغي / 16595