`Abdur-Rahman bin Samurah (May Allah be pleased with him) reported: The Messenger of Allah (PBUH) said to me, "Do not ask for position of authority. If you are granted this position without asking for it, you will be helped (by Allah) in discharging its responsibilities; but if you are given it as a result of your request, you will be left alone as its captive. If you take an oath to do something and then find a better alternative, you should adopt the latter and expiate for your oath."[Al-Bukhari and Muslim].
By rulership is meant caliphate or any other rank affiliated to its hierarchy. Yet, it is undesirable to be eager or to strive for such an extraordinary position as it entails a heavy responsibility and one may face a sufficient difficulty in being absolved from it. However, if a man gets it without solicitation, he should accept it. The other part of the Hadith concerns swearing. Somebody takes an oath to do something but he finds another work more rewarding and righteous. In such a situation he is advised to dissolve his oath and make expiation for it. Thereafter, he will be free to avail the advantageous option. As for the expiation of breaking an oath, there are four options: to set free a slave, or to feed an average-quality food to ten needy persons, or to provide clothes to them; and the expiator who cannot afford all that, should observe fasting for three days.