Those who hold that the voluntary prayer should be cut off when the prayer is called for cited the hadith, "When the prayer is called for, there is no prayer except the obligatory one," and the hadith of Abu Sa'id ibn al-Ma'la.

The questioner : May Allah preserve you, Shaykh. This man cited evidence that cutting off the voluntary prayer when the prayer is called for is better than continuing it, whether he is in the first or second unit. His evidence is as follows: First: The hadith of the chapter Second: The hadith
Third: The hadith of Abu Sa'id ibn al-Ma'la, who said: كنت أصلي فناداني رسول الله صلى الله عليه وسلم فلم أجبه فقلت : يا رسول الله إني كنت أصلي قال : ألم يقل الله تعالى : يَا أَيُّهَا الَّذِينَ آمَنُوا اسْتَجِيبُوا لِلَّهِ وَلِلرَّسُولِ إِذَا دَعَاكُمْ لِمَا يُحْيِيكُمْ I was praying when the Messenger of Allah (peace and blessings be upon him) called me, so I did not respond. I said: "O Messenger of Allah, I was praying." He said: "Did not Allah the Exalted say: 'O you who believe, respond to Allah and to the Messenger when he calls you to that which will give you life'?" And in the narration of Abu, he said: .
Fourth: The hadith: He says, he saysThe questioner : The sum of these pieces of evidence constitutes a single proof for what he said. May Allah preserve you, what do you say about this evidence of his, and is it suitable for citation? Give us a ruling, and may Allah reward you.

The Shaykh : Hand me the paper.
I say: The scholars have different opinions on this issue. Some said: It is not permissible to cut off the voluntary prayer until one completes it, unless one fears that the imam will finish the prayer before one completes it. This is the prescribed view in the Hanbali school, may Allah have mercy on them. They cited as evidence for this the saying of Allah, Blessed and Exalted is He: They said: Cutting off the prayer invalidates it, and Allah has forbidden it. They also said: When a person begins an act of worship, it is disliked for him to cut it off because of the turning away from the worship of Allah the Exalted after engaging in it.
Some of the scholars said: When the prayer is called for, it is obligatory to cut off the voluntary prayer immediately, whether one has prayed one unit or two. They cited as evidence the saying of the Prophet (peace and blessings be upon him): The first group responded to this by saying: His saying: means there is no prayer to be started, because the iqamah is a notification of entering the prayer.
So now you have a voluntary prayer and an obligatory prayer. You do not start the voluntary prayer, and there is nothing in the hadith indicating that there is no prayer, meaning: there is no prayer to be started and no prayer to be completed. It is ambiguous. As for the other evidence mentioned by the questioner, , there is no proof in it because the imam was not his imam, and he did not enter with him. He does not become an imam unless he enters the prayer with him, and he has not entered yet.
As for the hadith of Abu Sa'id al-Ma'la, there is no proof in it either. It only contains proof that when the Prophet (peace and blessings be upon him and his family) called a person who was praying a voluntary prayer, he must respond to him and not turn away from him. It does not address this issue. As for the fourth, , yes, there is no doubt that the obligatory prayer is better than the voluntary prayer. But this man will not miss the obligatory prayer because of the saying of the Prophet (peace and blessings be upon him): So if he is occupied with this voluntary prayer, the obligatory prayer will not be lost on him; he will perform it.
As for what I see in this issue, I see that if he is in the second unit, he should complete it briefly, and if he is in the first, he should cut it off. The reason for this is that if he is in the second unit, he has caught a unit of the prayer before it was prohibited for him to start the prayer. And the Prophet (peace and blessings be upon him) said: This opinion, as you see, is a middle position between those who say: complete it unless you fear the imam will finish before you, and those who say: cut it off immediately. This is the middle position between them, and it is the one we choose. And success is from Allah.