Re: Azab-e-Qabar!
Peace Queen_24,
We agree upon that the torment in graves clearly mentioned in hadiths by our beloved Prophet Muhammad 
However, if you’r trying to convince a non-muslim through reference from the Holy Quran then the close reference you can get in Surah Al Ghafir also know as Surah Al Momin [Chapter 40 verse 45-46]:
“So Allah protected him from the evils they plotted, and the people of Pharaoh were enveloped by the worst of punishment - The Fire, they are exposed to it morning and evening. And the Day the Hour appears [it will be said], "Make the people of Pharaoh enter the severest punishment.”
In above verses Almighty Allah says: “and the people of Pharaoh were enveloped by the worst of punishment”. ← This refers to drowning in the sea,
“The Fire, they are exposed to it, morning and evening” ← then being transferred from there to Hell, for their souls are exposed to the Fire morning and evening until the Hour begins. When the Day of Resurrection comes, their souls and bodies will be reunited in Hell.
Almighty Allah says: "And on the Day when the Hour will be established (it will be said to the Angels), “Admit Pharaoh’s people to the severest torment!”. ← meaning, more intense pain and greater agony.
The verse contains one of the major proofs used by the “Ahl-us-Sunnah” to prove that there will be torment in the grave during the period of “Al-Barzak”. The phrase: “The Fire, they are exposed to it, morning and evening”.
But the question arises here that this verse was undoubtedly revealed in Makkah, but they use it as evidence to prove that there will be torment in the grave during the period of Al-Barzakh. For this **Imam Ahmed recorded from Aisha, may Almighty Allah be pleased with her, that a Jewish woman used to serve her, and whenever Aisha r.a. did her a favor, the Jewish woman would say, “May Almighty Allah save you from the torment of the grave.”
Aisha r.a. said, “The the Messenger of Almighty Allah came in, and I said: O Messenger of Allah, will there be any torment in the grave before the Day of Resurrection?”
He said,
No, who said that?
I said, “The Jewish woman, whenever I do her a favor, she says: May Almighty Allah save you from the torment of the grave.”
The Messenger of Almighty Allah said: "The Jews are lying, and they tell more lies about Almighty Allah. There is no torment except on the Day of Resurrection.
Then as much time passed as Allah willed should pass, then one day He came out at midday, wrapped in his robe with his eyes reddening, calling at the top of his voice: “The graves is like patches of dark night! O people, if you knew what I know, you would weep much and laugh little. O People, seek refuge with Almighty Allah from the torment of the grave, for the torment of the grave is real**”.
This chain of narration in Sahih according to the conditions of Al-Bukhari and Muslim, although they did not record it.
It was said, “How can this report be reconciled with the fact that the verse was revealed in Makkah and the verse indicates that there will be torment during the period of Al-Barzakh?”.
The answer is that the verse refers to the souls (of Pharaoh and his people) being exposed to the fire morning and evening; it does not say that pain will affect their bodies in the grave. So it may be that this has to do specifically with their souls. With regard to there being any effect on their bodies in Al-Barakh, and their feeling pain as a result, this is indicated in the Sunnah, in some hadiths which mentioned below.
It was said this verse refers to the punishment of the disbelievers in Al-Barzakh, and that it does not by itself imply that the believer will be punished in the grave for his sins. This is indicated by the Hadith recorded by** Imam Ahmed from Aisha, may Almighty Allah be pleased with her, according to which the Prophet entered upon Aisha r.a., when a Jewish woman was with her, and she (the Jewish woman) was saying “I was told that you will be tried in the grave.”.
The Prophet was worried and said: “Only the Jews will be tested”. Aisha r.a., said: "several nights passed then the Prophet said: “Verily you will be tested in the graves.”
Aisha r.a., said: “After that, the Prophet used to seek refuge with Allah from the torment of the grave**.”
This was also recorded by Muslim. It could be said that this verse indicates that the souls will be punished in Al-Barzakh, but this does not necessarily imply that the bodies in their graves will be affected by that. When Almighty Allah revealed something about the torment of the grave to His Prophet , he sought refuge with Allah from that.
and Almighty Allah knows best.
References:
***Holy Quran Chapter 40 verse 45-46.
***Tafsir by Ibn-Kathir
***Hadith Sahih Bukhari Book “Inocations” Hadith No. 377 [Chain of narrators are "Uthman bin Muhammad ← Jarir bin Abdul Hameed ← Mansur bin Al Matamar ← Shaqayaq bin Salmah ← Masrouq bin Al Ajda ← Aisha bint Abin Bakar r.a.] ***
Hadith Malik’s Muwatta Book "The Eclipse Prayer’ Hadith No. 12.1.3
***Hadith Sahih Muslim Book "The Book of Prayers (Kitab Al-Salat), Hadith No. 1212 - 1214 [Chain of narrators of some hadith are "Hroon bin Saeed ← Harmlah bin Yahya ← Abdullah bin Wahab ← Younus bin Yazid ← Al Zuhri ← Urwa bin Al Zubayr ← Aisha bin Abi Bakar r.a.] ***
