It is narrated from Sayyiduna Ibn Umar (may Allah be pleased with them both) that it was said to Sayyiduna Umar (may Allah be pleased with him), "Will you appoint a successor (caliph)?" He replied: "If I do not appoint a successor, then one better than me did not appoint one, meaning the Prophet (peace and blessings be upon him). And if I do appoint one, then one better than me did appoint one, meaning Sayyiduna Abu Bakr (may Allah be pleased with him)."
Hadith Referenceمسند احمد / مسند الخلفاء الراشدين / 299