Sayyiduna Abd al-Rahman bin Samurah (may Allah be pleased with him) narrates that the Messenger of Allah (peace and blessings be upon him) said: "O Abd al-Rahman! Do not ask for leadership, for if leadership is given to you because you asked for it, you will be left to it; but if it is given to you without asking, you will be helped by Allah. And when you swear an oath about something and something else is better than it, do that and give the expiation for your oath."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الأيمان / 19947