We appreciate your keenness to take care in raising your children, which is something that many people are careless about, even though there are commands in the Qur’aan and Sunnah which enjoin protecting oneself and one’s family from the Fire, being sincere towards them, taking care of them and paying attention to their spiritual affairs such as prayer, and making them sleep in separate beds. 

Allaah says (interpretation of the meaning): 

“O you who believe! Ward off yourselves and your families against a Fire (Hell) whose fuel is men and stones, over which are (appointed) angels stern (and) severe, who disobey not, (from executing) the Commands they receive from Allaah, but do that which they are commanded.”

[al-Tahreem 66:6]

It was narrated that ‘Abd-Allaah ibn ‘Umar said: I heard the Messenger of Allaah (peace and blessings of Allaah be upon him) say:

“Each of you is a shepherd and each of you is responsible for his flock. The ruler of the people is a shepherd and is responsible for his flock. A man is the shepherd of his household and is responsible for his flock. A woman is the shepherd of her husband’s house and children and is responsible for her flock. The slave is the shepherd of his master’s wealth and is responsible for it. Each of you is a shepherd and each of you is responsible for his flock.” 

Narrated by al-Bukhaari (853) and Muslim (1829). 

It was narrated that Ma’qil ibn Yasaar said: I heard the Prophet (peace and blessings of Allaah be upon him) say: “There is no one whom Allaah puts in charge of a group of people then he fails to take care of them, but he will not smell the fragrance of Paradise.” 

Narrated by al-Bukhaari (6731). 

Your noticing your son’s movements is indicative of your concern to make him get used to good attributes and avoid bad attributes. This is a good thing, but at the age which you say your son is – four years old – sexual urges have not appeared in the majority of children. Some research has shown that it is possible for sexual urges to appear in some children before puberty, which is manifested in playing with the genitals for the purpose of sexual enjoyment. Some educators believe that this habit begins at the age of nine in ten percent of children, and others think that it may start between the ages of two and six. [See: ‘Adnaan Saalih Bahaarith: Mas’ooliyat al-Abb al-Muslim fi Tarbiyat al-Walad fi Marhalat al-Tufoolah, p. 468] 

A father often sees a child of this age putting his hand on his genitals without noticing, and if he is told, he will pay attention and remove his hand.  

The reason for that in some cases may be because there is an itch or an infection in that place, because the mother has been overzealous in cleaning him, or the cause of the infection may be negligence in cleaning the child after urinating or defecating. 

Another reason why a child may be interested in his private part is that he has been given the opportunity to play with it by being left naked for lengthy periods, so he starts to look at it and play with it. What should be done is to make the child get used to being covered from a young age, and put him off the idea of remaining naked. 

If the child is seen placing his hand on his private part, he should be distracted with something else, such as giving him a toy or a cookie, or by hugging him and kissing him. 

The aim is to distract him from this habit by simple means without making a fuss. There is no need to scold him harshly, because that will only make him more curious about that area and find out why he isn’t allowed to play with it. 

There is nothing wrong with asking the child if he has an itch or a pain in that area which is making him play with himself. 

Op.cit., p. 472 

With regard to your son’s issue in particular, we think that you should make sure that there is no problem in his clothes or body that is making him do that. Try to dress him in loose underwear and do not leave him wearing his outer pants only. 

Whatever the case: 

We advise fathers and mothers that it is essential to make their children get used to being covered and modest, and not let them wear short clothes, whether they are male or female. They should get used to wearing concealing clothes when they are still small, so that they will grow up chaste and decent. 

Shaykh Muhammad ibn Saalih al-‘Uthaymeen (may Allaah have mercy on him) said: 

It is well known that if a person is influenced by something when he is small, he will remain influenced by it when he grows up. Hence the Prophet (peace and blessings of Allaah be upon him) enjoined us to tell our children to pray when they are seven years old and to smack them (lightly)if they do not pray  when they are ten, so that they will get used to it, and the child will follow what he has gotten used to. 

Al-Liqa’ al-Shahri, 66/ question no. 9 

See also the answer to question no. 43485 and 9909. 

And Allaah knows best.