After the reappearance of Imam Mahdi, how long will it take for him to establish the rule of justice?
To this question, Imam Muhammad b. Ali al-Baqir (peace be upon him) has replied, "For a full eight months, he will have his sword unsheathed and will kill the enemies of God until God is satisfied." (Al-Ghaybah)
Based on the narrations that are available to us, he will reappear in Mecca. After the elite of his followers join him there, they will then advance toward 'Iraq, Sham (the present day Syria), and from there toward Jerusalem. Thereafter the lands of Europe, Turkey, China, Afghanistan, and of other regions will be conquered by him, and so after eight consecutive months of fighting, the rule of justice will be established, and peace and security will become prevalent. But about the duration of his rule, there is inconsistency amongst the narrations. Some of the related durations are as follows: 19 years and some months; seven years; 40 years; 10 years; 309 years, each year of which is equivalent to 20 or 40 normal years. And 40 days after his martyrdom or demise [depending on the narration], the earth and the sky will be demolished in preparation for the Day of Judgment.
Will any needy individuals remain after his rule has been established?
After the Imam rises and establishes the rule of justice, the earth will yield to him her treasures of mineral deposits and crops. The shares that rightfully belong to the destitute and poor will be exacted from the rich and the oppressors to be justly distributed, as the result of which no poor person will remain, to the extent that there will be no use for charities and Zakat. Imam Ja'far b. Muhammad al-Sadiq (peace be upon him) says, "The world will be revitalized by the implementation of justice, the sky will send down abundant rain, trees will reveal their fruit, and the earth will deliver her plants, embellishing herself for her inhabitants."
People will be so well-off that it has been narrated that on one occasion Imam Zaman will order the announcer to inform the people that whoever is in need of financial aid should stand up. From among the entire population only one person will stand up, proclaiming his need. Imam Zaman will tell him, "Go to the treasurer and tell him that Mahdi commands him to provide you with some money." At conveying the Imam's message to the treasurer, the latter will tell him, "Bring me your garment." Then the treasurer will fill it full. When the poor man turns away to leave, he will regret his request, saying to himself, "Why should I be the greediest of the nation of Muhammad?" So he will return it to the treasurer, but it will not be accepted, and Mahdi will tell him, "What we have granted, we will not take back."
In describing the time of Imam al-Mahdi's rule, the Prophet (peace be upon him and his progeny) has said, "People will be searching for someone poor who would accept charity or gifts from them, to no avail; they will put aside the Zakat of their wealth, but they will not find anyone to give it to, for all will be made well-off by Allah grace."
After Imam al-Mahdi establishes his rule, will there be any oppressors remaining in power?
The character trait of the universal rule of Imam al-Mahdi will be the worldwide maintenance of peace, security, justice, and the annihilation of the foundations of corruption, decadence, oppression, and crime. This has been the main purpose of all the prophets, but with the difference that the success of the latter and their successors following them was not as decisive. Nevertheless, establishing worldwide peace and security has always constituted one of their promises. And so the unpolluted souls of mankind at large, ever since the beginning of human history, have been waiting for the time when those promises would be realized. Now since Allah, His messengers, and their infallible successors do not breach their promises, they would not raise the hopes of people without a good reason. This means that this promise will certainly be realized and that a just government will be established, consisting of the aforementioned characteristics.
This promise is so vital and real that its realization can be considered the rationale behind the creation of humankind, a promise that once realized will lead to the unity of the whole of humankind under the banner of Tawhid and, by Allah's Mercy, the uprooting of disbelief, polytheism, and hypocrisy from amongst them. (11:118&123)
The narrations that express this are numerous. For instance, it has been recorded that Imam Hasan b. Ali al-Askari (peace be upon him) told his son, [Mahdi]: "It is as though I see you when Allah's support has been sent upon you, relief (faraj) has been achieved, your magnificence and greatness has risen... It is at this moment that the rule of truth will dawn and the darkness of evil will vanish from the scene of existence. Through your hands, Allah will break the oppressors' backs, will reinstate the religious sacraments, will enlighten the horizons of the world, and will establish calm and peace throughout the world. Your enemies will be disgraced and your friends esteemed and victorious. Not even a single oppressor, criminal, rebellious denier, encroaching enemy, spiteful opponent will remain on the face of earth, for whoever trusts in Allah, He will provide him sufficient support. Verily, Allah fulfils His wish and executes His definitive promise and will. Verily Allah has set a plan for everything."
Will sin be totally annihilated after Imam Zaman's rule has been established?
The most important motives for the human being's sinning are, on the one hand, his avarice in hoarding material wealth and, on the other hand, his sense of need for the goods of this world. If the human being possesses a sufficient amount of wealth, a good social reputation, if his mentality becomes Divine-permeated, if the world and her goods are belittled in his eyes, and he thus reaches the certainty that all Divine promises are true and as such will certainly be fulfilled, regardless of the aversion of the enemies and their effort to obstruct their realization; if he reaches the certainty that there will be a resurrection, a reckoning, that paradise and what it holds are incomparably superior to the life of this world – in such a case, there will be no motive for sinning. This is especially true based on a few narrations to the effect that at the commencement of the Imam's revolution, Satan will be slain by the Prophet in Jerusalem, hence putting an end to his tempting and decoying. (Tafsir al-Qummi)
Moreover, during that time there will be innumerable obstacles in the way of sinning – such as, the inescapable and universal rule of justice, the healthy and secure environment, and the general rejection of corruption and sin by society. Therefore, there will remain very little motive for sin, and at the same time there will be obstacles in its way, which means that sin will be at its lowest ebb.
There are also numerous narrations in this regard, such as: Imam Ja'far b. Muhammad as-Sadiq has thus described that era, "Illicit gender relationships, alcoholic beverages, and usury will vanish. People will turn their attention to worship and obedience; they will righteously honor their trusts. The evil people will perish, and the virtuous will remain."
In another narration, the Prophet is recorded as having given the following good tidings: "Allah will, through the Mahdi, relieve the hardships of the nation of Islam. He will enamor their [i.e. people's] hearts with the love of worship and obedience, and will make His justice universal. Allah will, through him, eradicate lies; He will destroy the spirit of violence and animosity, and will free them of the disgrace of bondage." (Al-Ghaybah)
Is it true that he will be martyred at the hands of a bearded old woman? How does such a crime take place despite the Imam's uprooting of oppression?
There are various narrations about Imam Zaman's martyrdom or demise; and as this event is due in the future, obviously the only way of unveiling the mysteries surrounding it is by studying the narrations related from the Infallibles in this regard. Nevertheless, the narration pertaining to the event of Imam Zaman being murdered by an old woman is not accepted as authentic by most scholars. This story has only been recorded in Ilzam al-Nasib and lacks authentic narration. However, if we do accept this narration, it must be noted that what is for certain is that the universal rule under Imam Zaman will be the rule of justice and equity, and as such the rule of the oppressors will be destroyed. However, this does not necessarily certify that there will be no possibility of individuals sinning.