وَإِذَا سَمِعُوا مَا أُنْزِلَ إِلَى الرَّسُولِ تَرَى أَعْيُنَهُمْ تَفِيضُ مِنَ الدَّمْعِ مِمَّا عَرَفُوا مِنَ الْحَقِّ يَقُولُونَ رَبَّنَا آمَنَّا فَاكْتُبْنَا مَعَ الشَّاهِدِينَ ﴿۸۳﴾ وَمَا لَنَا لَا نُؤْمِنُ بِاللَّهِ وَمَا جَاءَنَا مِنَ الْحَقِّ وَنَطْمَعُ أَنْ يُدْخِلَنَا رَبُّنَا مَعَ الْقَوْمِ الصَّالِحِينَ ﴿۸۴﴾

﴾83﴿ Wa izaa sami'oo maaa unzila ilar Rasooli taraaa a'yunahum tafeedu minad dam'i mimmmaa 'arafoo minalhaqq; yaqooloona Rabbanaaa aamannaa faktubnaa ma'ash shaahideen
﴾84﴿ Wa maa lanaa laa nu'minu billaahi wa maa jaaa'anaa minal haqqi wa natma'u ai yudkhilanaa Rabbunaa ma'al qawmis saaliheen

﴾83﴿ And when they hear the book that was revealed to the Messenger, you will see their eyes filled with tears Because of what they knew about the truth, he says, O our Lord, we have believed, so write us down with witnesses
﴾84﴿ And what is our excuse for not believing in Allah Almighty and in what has come to us from the truth, And we desire that our Lord will enter us with the righteous people

[83] This part is also connected to the previous qualities mentioned, with the difference being that the earlier qualities existed in them before they heard the Qur’an, whereas this fourth quality appears at the moment of hearing it. The verse suggests that the completion of the previous three traits is found in this fourth one:
“You see their eyes overflowing with tears” –
Question: The verb of flowing (tafīḍ) is attributed to the eyes, even though it is the tears that flow?
Answer: This is a form of exaggeration and vivid expression. Originally, it means their eyes fill up with tears, then the tears overflow. Or the preposition "min" (from) implies association: their eyes along with the tears are overflowing.
“From what they have recognized of the truth” –
The first “min” indicates the cause (i.e., because of their recognition).
The second “min” is partitive, meaning they weep upon recognizing some of the truth—and if they were to hear all of it, they would weep even more.
“They say...” – This demonstrates their lack of arrogance toward the truth.
“So write us among the witnesses” – This refers to the Ummah of Prophet Muhammad (peace and blessings be upon him), as described in:
Surah Al-Baqarah (2:143): “...so that you may be witnesses over mankind.”
Surah Al-Hajj (22:78)
This type of supplication was also made by the sincere among the Christians who accepted the truth when they heard it.
[84] This passage is a response to those who criticized the believers among the Christians, asking why they accepted another religion. Their reply is:
“And why should we not believe in Allah...” – This is a rhetorical question, meaning: there is no excuse at all for not believing.
“...and in what has come to us of the truth” – This refers to the Qur'an, and the phrase is either:
Conjoined (atf) with belief in Allah, or
A circumstantial clause (ḥāliyyah), describing the state while believing.
“And we hope...” (wa naṭmaʿ) – This can be:
Conjoined with nū’minu (we believe),
Or another circumstantial clause, implying: “while we hope”, with an implicit phrase like “we are those who hope.”
The summary:
There is a clear cause for belief—our hope for Paradise—and no obstacle preventing belief. When a reason exists and no barrier is present, belief becomes necessary.
“With the righteous people” – This refers to the Ummah of Prophet Muhammad (peace and blessings be upon him), based on the context of:
Surah Al-Anbiya (21:105): “My righteous servants shall inherit the earth.”
The word “ma‘a” (with) here can mean:
“In” (i.e., in Paradise with them),
Or implies an omitted phrase, like “in Paradise with the righteous.”