An oath is defined as a solemn appeal to a deity to stand as a witness to the binding nature of a promise or the truth of a statement.
The swearing of an oath is a common practice in all cultures and has been a procedure for many centuries. In the Roman tradition, oaths were sworn upon Jupiter Lapis or the Jupiter Stone located in the Temple of Jupiter, Capitoline Hill. Jupiter Lapis was held in the Roman Tradition to be an Oath Stone, an aspect of Jupiter is his role as divine law-maker responsible for order and used principally for the investiture of the oath taking of office. The concept of oaths is deeply rooted within Judaism. It is found in Genesis 8:21, when God swears that he will “never again curse the ground because of man and never again smite every living thing.” This repetition of the term never again is explained by Rashi, the pre-eminent biblical commentator, as serving as an oath, citing the Talmud for this ruling.
The first personage in the biblical tradition to take an oath is held to be Eliezer, the chief servant of Abraham, when the latter requested of the former that he not take a wife for his son Isaac from the daughters of Canaan, but rather from among Abraham’s own family. In the Judeo-Christian Tradition, this is held as the origination of the concept that it is required to hold a sacred object in one’s hand when taking an oath. (Wikipedia)
Likewise, in Islamic tradition, oaths are held in high esteem. To take a false oath is branded as a major sin. In addition to this, oaths can only be taken on Allah. Imam Ahmed reports that the messenger of Allah (Allah bless him and give him peace) said, “Whoever takes an oath upon other than Allah, has associated partners to Allah.”
Imam Kaasani in his manual of jurisprudence Badaa’i al-sanaa’i states that in pre-islamic times, the Arabs would take oaths upon whatever was gigantic, had immense benefit and regarded dangerous. They would swear upon the Earth, the Sun, the Moon, the night and day.
The essence of an oath is honouring and venerating that which is sworn upon. It is considered to be great and lofty in the sight of men. With this being the fundamental nature, oaths are synonymous to worship, and worship is exclusive for Allah alone. Therefore, just as worship of other than Allah is prohibited, swearing an oath on other than Allah bears the same ruling. Due to the common thread between the two, the messenger of Allah unified associating partners to Allah and swearing a false oath in a single sentence. Imam Bukhari reports on the authority of Abdullah ibn Amr’ that the Prophet (Allah bless him and give him peace) said, “Major sins include associating partners to Allah, disobeying ones parents and the swearing of false oaths.”
The Quran contains many oaths. Allah the Almighty takes an oath of Himself approximately seven times in;
1) Surah Nisaa verse 65
2) Surah Yunus verse 53
3) Surah Taghaabun verse 7
4) Surah Maryam verse 68
5) Surah Hijr verse 92
6) Surah Ma’aarij verse 4
7) Surah ath-Dhaariyaat verse 23
However, when one studies and ponders over the text of the Quran, he will become conscious of the fact that Allah the Almighty takes an oath on many of His creation. At times Allah is swearing upon the Sun, at times on the Moon, on other occasions on the stars, on the angels etc. So why does Allah take an oath on such creation? What do these oaths mean in the Quran?
Explanations for the oaths:
1) Some specialists in the exegesis of Quran are of the view that wherever an oath on a creation of Allah is mentioned, the word ‘rabb’ is omitted prior to the word. So in actual fact, these are oaths on Allah also. So the verses, “By the Sun,” “By the Moon,” “By the fig and the olive,” in reality are, “By the Lord of the Sun,” “By the Lord of the moon,” “By the lord of olive and the fig.”
The omitting of words is very common in the Quran. This is not a deficiency at all. It is evidence to its rhetoric and eloquence. Whatever is common knowledge and obvious is omitted for the sake of brevity. Furthermore, the omission of such words plays a vital role; it invites man to engage with the Quran and as result, the reciter builds a connection with the Quran to read beyond the text.
2) Another body of scholars are of the opinion that such phrases are in their literal meaning. Allah took oaths upon these creations as this was also the practice of the Arabs. So to add extra weight to the message, Allah communicated in a style common to the recipients.
3) Another famous opinion is that by taking oaths upon the creation, Allah is showing His greatness. Reason being, if the invention of an inventor is great, then the mere mention of such an invention entertains praise for the inventor. So Allah the almighty is swearing upon His inventions which display His greatness, which in reality equates to taking an oath on His majesty and grandeur. (al-Itqaan pp.505-508)
4) Another opinion suggests that Allah isn’t taking an oath on these creations, instead Allah is summoning these creations to witness what is about to be said. The sole purpose is to show mankind the submission and humbleness of creations far greater than them, so what stops them from submitting? These creations readily stand witness and accept the words of Allah. (Kashful Baari 2/515)
5) Abul Qasim said, “The taking of oath on any entity is primarily due to two reasons: either its virtue or its benefit.” For example, Allah takes an oath upon Mount Sinai, this is solely dues its virtue and merit. Whereas the oath on the fig and olive is principally due to the immense benefit it extends.
6) Other scholars have looked at the oaths from a different angle and commented that all oaths will fall under one of the three categories:
a) Oaths of Allah upon Himself
b) Oaths of Allah on His actions. For example, in Surah ash-Shams Allah says, “And [by] the sky and He who constructed it. And [by] the earth and He who spread it. And [by] the soul and He who proportioned it.”
c) Oaths upon the consequences of the actions of Allah. For example, Allah says in Surah an-Najm, “By the star when it descends.”
The different issues upon which oaths are taken upon:
1) Oaths to stress the necessity to believe in core principles. For example, Allah takes an oath on the angels to stress belief in the concept of monotheism,
“ By those [angels] lined up in rows And those who drive [the clouds]And those who recite the message, Indeed, your God is One, Lord of the heavens and the earth and that between them and Lord of the sunrises.(Surah as-Saaffaat 1-5)
2) Oaths to underline that the Quran is a divine revelation. For example: “Then I swear by the setting of the stars, and indeed, it is an oath – if you could know – [most] great. Indeed, it is a noble Qur’an.” (Surah al-Waqi’ah 75-77)
3) Oaths to underscore the authenticity of the Prophet (Allah bless him and give him peace). Allah says, “Ya, Seen. By the wise Qur’an. Indeed you, [O Muhammad], are from among the messengers, on a straight path.” (Surah Yasin 1-4)
4) Oaths to add weight to the reality of the reckoning in the Hereafter and the undeniable outcome of it. Allah says, “By those [winds] scattering [dust] dispersing. And those [clouds] carrying a load [of water]. And those [ships] sailing with ease. And those [angels] apportioning [each] matter. Indeed, what you are promised is true. And indeed, the recompense is to occur.” (Surah Adh-Dhaariyaat 1-6)
5) Oaths to emphasise the state of man. Allah says, “By the horses that gallop, panting, and the producers of sparks [when] striking. And the chargers at dawn, stirring up thereby [clouds of] dust, arriving thereby in the centre collectively, Indeed mankind, to his Lord, is ungrateful.” (Surah al-‘Adiyaat 1-6)
This answer was collected from DarulFiqh.com, which is operated under the supervision of Mufti Faraz ibn Adam al-Mahmudi, the student of world renowned Mufti Ebrahim Desai (Hafizahullah).