Aqsaam (oaths) in the Qur’an are a very fascinating subject that we should study and focus on more. There are a few components needed for a qasm (oath) to occur. One of them is the harf qasm, a letter that shows there is an oath being taken.

There are a few letters in the Qur’an that are used as harf qasm, for example, Allah ta’ala says “wal ‘aadiyaati dhabhaa”. The harf qasm in this oath is the letter wow (و).

Another harf qasm which does not appear very much in the Qur’an is the letter ‘taa’ (ت). The unique aspect of this letter is that it is only used for Ismul Jalaalah. You will never see the letter ‘taa’ being used to swear by other than Allah azza wa jal.

What is the difference between the harf wow and taa?

The harf taa is only used in very unusual circumstances, while harf wow is the standard harf qasm–the one that appears most in the Qur’an, and harf wow is used to swear by things other than Allah ta’ala.

The harf taa is used in a state of strong and overwhelming emotion, such as astonishment, anger, frustration and amazement.

Harf taa appears a total of nine times in the Qur’an: twice used by Allah azza wa jal (to swear by Himself), once in the speech of Ibrahim alayhi salaam, four times used by the brothers of Yusuf alayhi salaam, and twice in the speech of people in the hereafter.

Here are some examples:

When Ibrahim alayhi salaam was so angered and upset by his people worshipping the idols, he said:

تَاللَّهِ لَأَكِيدَنَّ أَصْنَامَكُم بَعْدَ أَن تُوَلُّوا مُدْبِرِينَ

“by Allah! I will definitely plot a plan (to destroy) your idols after you have gone away and turned your backs.” (21:57)

When the brothers of Yusuf alayhi salaam were just shocked that their father alayhi salaam would not forget and “get over” the alleged death of their brother–in their amazement they said:

تَاللَّهِ تَفْتَأُ تَذْكُرُ يُوسُفَ حَتَّى تَكُونَ حَرَضًا أَوْ تَكُونَ مِنَ الْهَالِكِينَ

“By Allah! You will never cease remembering Yusuf until you become weak with old age, or until you die!” (12:85)

The people of hell-fire, in their complete regret and anger with themselves say:

تَاللَّهِ إِن كُنَّا لَفِي ضَلَالٍ مُّبِينٍ  إِذْ نُسَوِّيكُمْ بِرَبِّ الْعَالَمِينَ

“By Allah! We were truly in a manifest error, when we held you (false gods) as equals with the Rabb of all that exists!” (26:97-98)

The Qur’an tells us of a future event, when a companion of Jannah begins to reminisce about a friend he had in the dunya that did not believe in the resurrection. Then a voice calls out and says:

هَلْ أَنْتُمْ مُطَّلِعُونَ

‘Will you look down? ‘ (37:54)

فَاطَّلَعَ فَرَآهُ فِي سَوَاءِ الْجَحِيمِ

“So he looked down and saw him in the midst of the fire, (37:55)

In his gratefulness to Allah, his happiness and relief he says:

تَاللَّهِ إِنْ كِدتَّ لَتُرْدِينِ وَلَوْلَا نِعْمَةُ رَبِّي لَكُنْتُ مِنَ الْمُحْضَرِينَ

“By Allah! You have nearly ruined me! Had it not been for the Blessing of my Rabb, I would certainly have been among those brought forth (to Hell).” (37:56-57)