The Muslims are those from whose tongues and hands other Muslims are safe and sound. The emigrants are those who leave behind and abandon those things God has prohibited.
Let us briefly analyze the above hadith. Notice the presence of the definite article (al in Arabic) before Muslim. What can be extrapolated from this is that there are ideal believers who enter an atmosphere of safety and security, having so immersed themselves in that atmosphere that they harm no one with their hands or tongues. This refers only to the true and ideal Muslims who leave their mark on all minds, not those who appear or claim to be so, or to those whose identity cards or passports have "Muslim" written on them. We understand this from the article used in the Arabic, which indicates something specific, definite. This is derived from the grammatical rule of the Arabic language: "When something is described by a definite article, the item's highest and most perfect condition is indicated." So, when one hears "the believer," the first thing that comes to mind is the most perfect meaning of "believer," and that is what is meant in this hadith.
Moreover, one cannot learn such a fine grammatical point by oneself, for it is a topic that belongs to formal education. Hence, such an educational experience was not possible for the Messenger of God; he was illiterate. Thus, he was not speaking his own thoughts, but rather he was relaying what the Eternal Teacher taught him to say. For this reason, there are many subtle grammatical points found in the Prophet's expressions and declarations, and there are no errors in usage.
Let us return to the above hadith: Real Muslims are people in whom one can feel confidence and trust, so much so that other Muslims can turn their backs on them without a second thought. One can entrust a family member to such people without fear; this person will suffer no injury from the hand or tongue of the Muslim. If one were to attend a gathering with a true Muslim, one could leave in full confidence that no one will gossip about one, nor would one have to listen to gossip about others. Such Muslims are as sensitive to the dignity and honor of other people as they are to their own. They do not eat; they feed others. They do not live for themselves; they live to enable others to live. They will even sacrifice their spiritual pleasure for others. I derive all these meanings from the fact that the definite article in Arabic also means hasr; a restraining, a devotion to a specific purpose.
Security and Muslims
Etymologically speaking, the word Muslim and the verb sa-li-ma both come from the root silm. This means that for Muslims, every matter takes place in line with silm (security), salamah (safety), and Muslim-ness. Muslims are seized by such a divine attraction that all of their actions take place around this powerful center.
They greet everyone with salaam, thereby placing love for themselves in everyone's heart. They end their prayers with salaam. All people, jinn, angels, and conscious creatures receive their salaam. That is, they exchange greetings with invisible creatures as well. Until now, no other people have extended this circle of greeting to such a degree as have the Muslims. Islam consists of performing such principal duties as fasting, giving alms, performing the Hajj, and striving to profess the faith. This means that they set sail on the sea of safety and security by obeying the command: Enter safety (Islam) whole-heartedly (2:208). Those who throw themselves into that sea emanate safety and Islam in every condition. No one sees anything but goodness in the actions and behavior of such people.
Why the tongue and hand?
As in every statement of our master, peace and blessings be upon him, every word in the hadith mentioned above was chosen carefully. Why did he choose the hand and the tongue to speak about? Of course there are many subtle points related to this choice. A person can harm someone in two ways: either directly or indirectly. The hand represents physical presence (directly), and the tongue represents absence (indirectly). People either attack others directly, physically, or indirectly, through gossip and ridicule. Real Muslims never engage in such activities, because they are supposed to always act justly and generously, whether they are acting directly or indirectly.
The Prophet mentioned the tongue before the hand because in Islam one can retaliate for what has been done with the hand. However, the same is not always true for damage done indirectly through gossip or slander. Thus, such action can easily cause conflict between individuals, communities, and even nations. Dealing with this type of harm is relatively more difficult than dealing with the harm caused by the hand, and this is the reason why the Prophet mentioned the tongue before the hand. On the other hand, the value of Muslims before God has been indicated. Being a Muslim has such a great value before God that other Muslims must control their hands and tongues in their actions toward them.
Another important moral dimension of Islam is that Muslims must keep at bay things that will harm others, whether physically or spiritually, and they must do their best not to harm others. Let alone not causing harm, every segment of Muslim society must also represent safety and security. Muslims can be real Muslims to the extent that they carry within themselves a feeling of safety and that their hearts beat with trust. Wherever they are or wherever they live this feeling that derives from al-salaam is revealed. They wish for safety upon departure, adorn their prayers with greetings, and send salaams to other believers when they end their prayers. In all probability, it is inconceivable that people who lead their whole lives in such an orbit of salaam would embark on a path that is contrary to the basic principles of safety, trust, soundness, and worldly and other-worldly security, thus causing harm to themselves or to others.
It would be useful to examine the very essence of these points: True Muslims are the most trustworthy representatives of universal peace. They travel everywhere with this sublime feeling, nourished deep in their spirits. Far from giving torment or suffering, they are remembered everywhere as symbols of safety and security. In their eyes, there is no difference between a physical (direct) or a verbal (indirect) violation of someone's rights. In fact, in some cases the latter is considered to be a greater crime than the former.
 Bukhari, Iman, 4.
 Bukhari, Iman, 20; Muslim, Iman, 63.