Imam Jawad (AS) is the ninth Shiite Imam. His father is Imam Reza (AS), and his mother’s name is  Sabikah. His original name is “Muhammad,” but his epithet is “Jawad,” meaning “a very generous person.” He was born on 195 H (810 AC) in Medina. (1)

Generally, Shiite Imams carried prestige among their tribe and were respected by everyone. Many Shias believed that Imams were merely knowledgeable people who gained their knowledge only from their ancestors and they were not extraordinary. However, the imamate of Imam Jawad (AS) made all the Shias think differently and change their minds. He was only eight years old, when his father, Imam Reza (AS), was martyred. According to hadiths, the earth cannot be without an Imam. Accordingly, Imam Reza (AS) said:
The earth cannot be without any of us, Imams, whether he is known by the people or hidden from them. (2)

Shias didn’t know who would be their leader after Imam Reza (AS). But, he introduced Imam Jawad (AS) as his successor (3) and showed the Shias that “Imam” was not an ordinary person and he could be the leader of the whole Shias despite being young. 

Knowledge is a sign of imamate 

The hadiths suggest various signs for Imams so that we can differentiate between the truly chosen Imams by Allah and impostors. One of the most significant signs is that he is the most knowledgeable person of his time. 

Prophet Muhammad (PBUH & HP) said:
Do not try to teach something to Ahlul Bayt because they are far more knowledgeable than you. (4)
Regarding this, Imam Sadiq (AS) acknowledged:
Indeed Ali (AS) was a knowledgeable person whose knowledge will be passed to his successors and no knowledgeable person (an Imam) dies except to leave their knowledge to someone else. (5)
He also said:
The successor of an Imam attains the knowledge of the previous Imam in the last moment of his life. (6)

The debates of Imam Javad (AS) with religious scholars

Ma’mun was one of the Abbasid Caliphs who lived during the same period as Imam Reza (AS) and Imam Jawad (AS). During his caliphate, the Shia population increased dramatically which intimidated him. Due to this fact, he lied that Imam Reza (AS) was his successor and led people to believe that he was not an enemy of Shiite Imams. But at last, he killed Imam Reza (AS). After Imam Reza (AS), Imam Jawad (AS) was his most important enemy. He made Imam Jawad (AS) marry his daughter so that he could deceive people longer. 

Many of the Abbasid royalties were against Ma’mun’s decision, as they believed that the boy was too young and he wasn’t a knowledgeable person. Ma’mun proposed that they should test the knowledge of Imam Javad (AS), in order to show everyone how extraordinary he is. Imam Javad (AS) was only nine years old at that time. 

One of the most knowledgeable religious scholars in those times, Yahya ibn Aktham, volunteered to have a discussion and debate with Imam Javad (AS). 
During the discussion, Yahya ibn Aktham asked Imam Javad (AS) about a person who has killed an animal while making Hajj; what should he do? (During the Hajj ceremony, it is forbidden for the pilgrims to kill any creature).
Imam Jawad (AS) said that it depends: Did he kill it in Mecca or outside of it? Did he know about this law or not? Has he done it intentionally or unintentionally? Was he free or was he a slave? Was it his first time? Was it a bird or something else? Was it a small animal or a big one? Is he ashamed of what he did or not? Did he do it at night or during the day? Was it Umrah (a special type of Hajj) or regular Hajj? 
Yahya was so surprised that he couldn’t answer the twelve questions of Imam Jawad (AS), but instead, Imam Javad (AS) answered them one by one and explained the rules to everyone. 
Ma’mun told people that “Now do you see what I was telling you?” (7)
During another session, Yahya asked Imam Jawad (AS) about a hadith from the Prophet (PBUH & HP) that Sunni narrators had recorded. The hadith said “Once Gabriel came to the Prophet (PBUH & HP) and told him ‘O Muhammad! Allah told you to inform Abu-Bakr that I am satisfied with him. Is he satisfied as well?” Yahya questioned Imam Javad (AS) about the authenticity of this hadith.
Imam Jawad (AS) said, “I do not deny the privileges of Abu-Bakr … but this hadith is contrary to the verses of the Quran.” Imam Javad (AS) stated he wouldn’t deny the privileges of Abu-Bakr because he was surrounded by Sunnis and it was so dangerous for him to speak out against Abu-Bakr.
Then he said, “The holy Quran says 
‘Surely We have created man, and We know the promptings of his heart, and We are nearer to him than even his jugular vein.’ (50:16) 
Then why should Allah ask Abu-Bakr whether he is satisfied with him or not while Allah already knows it?”
Yahya referred to another hadith that claims Abu-Bakr and Umar on the earth are like Gabriel and Michael in the skies. 
Imam Javad (AS) said “This hadith cannot be accepted as well, because Gabriel and Michael never worshiped anyone except Allah, while Abu-Bakr and Umar spent most of their lives as polytheists and worshippers of idols.” 
Yahya added that Abu-Bakr and Umar are the lords of the elderly in Paradise.
Imam Javad (AS) stated that it is impossible as people in Paradise are all young not old. Umayyad dynasty made this fake hadith because they didn’t like the authentic one narrated by the Prophet (PBUH & HP) that reads, “Hassan (AS) and Hussain (AS) are the lords of young people in Paradise.” (8)
Yahya said it also has been narrated that Umar is the one who illuminates Paradise.
Imam Javad (AS) responded that it is also impossible. Do you think that Paradise is not illuminated by the Angles and Prophets like Adam (AS) and Muhammad (PBUH & HP) but rather by Umar?!
Yahya said it has been claimed that the angels talk with the tongue of Umar.
Imam Jawad (AS) said that he does not deny the privileges of Umar. However, Abu-Bakr was better than Umar as he said, “I have a Satan that sometimes tempts me, so if you see me deviating, stop me.” 
Yahya asked many other questions about Abu-Bakr and Umar, and Imam Javad (AS) answered them all. (9)   
Not only Imam Javad (AS) did not fail to answer the questions, but also, he posed more questions that even the most knowledgeable scholars felt incapable of disputing with Imam Javad (AS). These debates happened when Imam Javad (AS) was only 8 or 9 years old. 
As it might be apparent, Shiite Imams were extraordinarily knowledgeable, and their knowledge was given to them by God not by learning in classes and the like. They were the most knowledgeable individuals in their era regardless of their age.

Resources

1.  I’lam al-Vara, Sheikh at-Tabarsi, vol.2, pg.91
2.   Kamal ad-Din, Sheikh Saduq, vol.1, pg.202
3.  Al-Kafi, Sheikh Koleini, vol.1, pg.320
4. Mu’jam al-Kabir, at-Tabarani, vol.5, pg.166
5.  Al-Kafi, Sheikh Koleini, vol.1, pg.221
6.  Al-Kafi, Sheikh Koleini, vol.1, pg.275
7.  Al-Ih’tijaj, at-Tabarsi, vol.2, pg.444
8. Sunan al-Kubra, Nasa’i, vol.7, pg.460
9. Al-Ih’tijaj, at-Tabarsi, vol.2, pg.446-448
    

Islam is a complete way of life, which deals extensively on both the spiritual, as well as the physical well-being of its adherents. Hygiene in Islam is one of the great privileges in Islam. This write-up is aimed at examining the Islamic perspective on physical cleanliness.

The significance of Hygiene in Islam

Cleanliness and purification is an essential part of Islamic life, and in fact, the philosophy behind it in Islam is much beyond the superficial concept of the conventional cleanliness. 

In the Quran, Allah says:

"…Indeed Allah loves the penitent, and He loves those who keep clean." (2:222)

Similarly, one of the injunctions that were revealed unto the Prophet (PBUH&HP) following his call to rise and warn was the purification of his garments [i]. The Holy Prophet (PBUH&HP) and the infallible leaders (AS) have instructed the Muslims to maintain cleanliness and have seriously frowned at dirtiness and untidiness [ii].

Hygiene in Islam at Birth and Death 

When a child is born, Islam enjoins the Muslims to maintain a high level of cleanliness and purity concerning him/her, as this has an impact on the mind and soul of that child. If the parents neglect this duty, they should answer before God for the consequences. Similarly, circumcision of the male child-preferably on the seventh day- is a mandatory Islamic custom. That is because it “prevents the child against the possible infection of the male genital organ" [3].

Also, at death, it is mandatory to perform full body washing ablution (Ghusl) for a dead body of a Muslim.

Ablutions (Wudu) & (Ghusl)

In addition, ablution (Wudu) and body purity are considered as very crucial conditions for the validity of prayer (Salat), which is the most significant act of worship in Islam. In fact, on a normal circumstance, a Muslim cannot offer his prayers with an unclean body, clothes or use dirty premises. They are enjoined to use clean, pure water and keep it safe from any form of impurities.

Various full body-washing ablutions (Ghusl) after the release of semen, expiration of monthly period or childbirth, touching of dead bodies, etc. are prescribed in Islam to observe some religious obligations.

Personal Hygiene in Islam

Cleansing of their genitals with water or other cleansing materials after passing urine or excreta are parts of the Islamic customs. Similarly, Muslims on an interval are enjoined to clip their nails and to shave the hair in their armpit and pubic area. Likewise, they are also enjoined to trim their mustaches in order to avert oral intakes, keep oral hygiene, good physical appearance and to make use of fragrance. Similarly, Islam emphatically enjoins a Muslim to keep his clothes, houses, and environment clean. Prophet Muhammad (PBUH&HP) said: “The Arch Gabriel continuously ordered me to clean my teeth until I thought it would be made compulsory” [4].

Food Hygiene

In the Quran and narrations (Hadiths) of the Prophet (PBUH&HP) and the infallible Leaders (Ahl-al-Bayt) (AS), great emphasis has been placed on the cleanliness and purity of the foods and drinks. For the importance attached to the well-being of the body as well as that of the soul, Islam has enjoined the entire human beings and the believers in particular to consume hygienic, pure and lawful foods [iii].  Similarly, it forbids the consumption or usage of all unhygienic, impure and unlawful foods/drinks (such as blood, dead animal, dogs, pig, intoxicants, etc.) and they are considered great sins in Islam and punishable under the Islamic laws.

Conclusion

Cleanliness and personal hygiene in the Islamic custom are aimed at keeping both the body and mind healthy. In some cases such as ablution (Wudu) and body-washing ablution (Ghusl), body purity is considered a prerequisite for the observance of prayers. Moreover, body purity is one of the necessary conditions for attaining an inner or spiritual purity. It is based on this that Muslims are strictly enjoined to uphold high standards of physical hygiene and to be ritually cleaned whenever possible.

Notes:

[i] (74:4)

[ii] The Prophet (PBUHHP) said: "Verily, Islam is [the religion of] cleanliness, so cleanse yourselves. For surely, only the cleanly enter Paradise" [1] and "Observe cleanliness in every respect you are capable, for indeed God based Islam on cleanliness" [2].

[iii]. "O humankind! Eat of what is lawful and pure in the earth…" (2: 168). "O you who have faith! Eat of the good things We have provided you, and thank Allah if it is Him that you worship." (2: 172)

References:

1. Nahj al-Fasahah, Vol. 2, P. 998.
2. Ibid.
3. Ibrahim Amini, Principles of upbringing children, chapter 25 P. 176 (published by Ansariyan publications, Qum)
4. Bihar al-Anwar, vol. 76, P. 126.