Ignorance of Islamic acts is a kind of nomadism

The above two verses which flay the infidel Bedouins are clear regarding the fact that the nomads were deserving of criticism not because of their being occupants of desert. It was because of their ignorance of articles of Islamic acts and belief. For those Bedouins who followed the Islamic religion, the Holy book has praised them in the third verse. They have been promised Divine Mercy.

On the basis of this, people who avoid learning Islamic rules and regulations and those who keep away from the centres of religious knowledge are in fact, nomads, and the verse denouncing the desert Arabs also applies to them even though they are living in cities.

The respected Imam Ja'far as-Sadiq (a.s.) remarked: 
"Learn the rules of religion. Those of you who do not learn about religion are nomads. As the Almighty Allah says in His book,'Why does not a company from you goes to learn about religion so that when they come back they can warn their people in order they may become fearful (of disobeying Allah).'" 
(Behaarul Anwaar, Book of Aql)

Thus one who does not try to learn about religion and articles of faith is a desert occupant. The Imam (a.s.) also told his followers: 
"Knowledge of the Divine religion is incumbent on you. And do not become a nomad. Because if you fail to comprehend a religious act, Allah will not look upon it with Mercy on the Day of Qiyamat and He will not purify that deed." 
(Shaheed-e-Thani)

One who learns but does not act upon it is also a nomad

Muhaddith Faiz writes in Waafi that it is possible that the above pronouncement may also apply to those who learn about the Islamic rituals and practices but fail to act upon them. He also quotes a tradition from Imam Ja'far as-Sadiq (a.s.) to prove this point. Allamah Majlisi (r.a.) states in the Sharh of Al-Kafi that some scholars are of the opinion that being a nomad in the present time applies to those who after acquiring religious instructions, do not act upon them and remain aloof from Islamic knowledge.

Amirul Momineen Ali (a.s.) says: 
"A man says that he has migrated, though in fact he has not. Because a migrant is the one who abandons sins and does not even go near them. And a person says that he has fought in the way of Allah but in reality he has not, because Jehad is the leaving of sinful acts and a war against enemy inside our own self. Whereas many people go out to fight not for the obedience and satisfaction of the Lord. Their motive is only to gain fame so that people may praise their bravery and fearlessness." 
(Behaarul Anwaar vol.15)

Desert of ignorance and negligence

From the Quranic verses, the traditions and writings of the Islamic scholars we can conclude that nomadism implies the condition of a person who is ignorant and unaware of Allah Almighty's Nobility of which human beings are capable and the eternal bliss which one can achieve, and instead he is totally immersed in the desires of this transient world. He is oblivious to righteousness and does not refrain from committing any sin or evil. He does not care to acquire knowledge (Ma'refat), nor does he pay attention to good deeds, that would fetch him eternal rewards in the Hereafter. It would surely deprive a person of salvation and eternal bliss.

Hijrat (migration) is the exact opposite of Nomadism. Nomadism after Hijrat (migration) implies that a person migrates to Islam and obtains knowledge of religion and then reverts to his former ways. It can be said that performing some good actions for some time and then leaving them is also a kind of reverting to nomadism. The denouncement is valid only if the person does this due to laziness and sloth and not due to some real hindrance or helplessness. It is necessary to continue to perform good actions once we have begun them. As far as possible we should not discontinue them.

Jabir Johfi quotes Imam Ja'far as-Sadiq (a.s.) to have said: 
"I like to continue good actions so that I become habitual in them. If I could not perform a particular deed in the day I make up for it during the night and if I do not perform an action during the night I make up the following day. Certainly the best of the deeds near Allah are those which one continues. Hence all the deeds of the week are presented to Imam (a.s.) every Thursday and the deeds of the month at the end of the month and all the deeds of the year at the middle of Shabaan. So if you begin a good ritual, keep at it for the whole year." (i.e. continue it for at least a year).
(Behaarul Anwaar)

Neglecting religious knowledge

If a person begins to acquire religious knowledge but later discontinues the same it is considered reverting to nomandism by some. However, it is Haraam only if his religious education is obligatory (i.e. if he leaves it, he will go astray). However, it is incumbent to continue acquiring knowledge till the end of one's life so that one can continue to perform good deeds with sincerity and purity of intention. In this way a person becomes righteous and deserving of the rewards of his good deeds, both in this world and the hereafter.

As the Holy Prophet (s.a.w.s.) has said:
"Acquire knowledge from the cradle to the grave."