Praise be to Allah.
The seven modes of recitation were all narrated from the Prophet (blessings and peace of Allah be upon him) in mutawaatir reports. This is something that is well known in Islam, therefore it is permissible to recite in any one of them. We have explained this matter in detail in fatwa no. 178120.
With regard to combining two or more modes of recitation in one prayer or one rak‘ah or outside the prayer, the scholars differed concerning that and there are three points of view:
The first view is that of those who regard it as permissible in all cases, based on the fact that all of the modes of recitation from Allah, may He be glorified. Ibn al-‘Arabi said in Ahkaam al-Qur’an (2/613):
Once the modes of recitation are proven and the pronunciation is determined, no one is obliged to recite only with the mode of recitation of one person, such as Naafi‘, for example, or ‘Aasim. Rather it is permissible for him to recite al-Faatihah pronouncing its words according to three different modes of recitation, because all of it is Qur’an. End quote.
In Majmoo‘ Fataawa Ibn Taymiyah (22/445) it says:
He was asked about a man who leads people in prayer and recites according to the recitation of Shaykh Abu ‘Amr. If he recites according to the recitation of Warsh or Naafi‘, as they are different recitations, even though he mostly recites according to the recitation of Abu ‘Amr, will he be sinning or does that detract from his prayer or will it be rejected?
He replied: It is permissible to recite part of the Qur’an according to the recitation of Abu ‘Amr and part according to the recitation of Naafi‘, whether that is in one rak‘ah or over two rak‘ahs, and whether that is outside of prayer or in the prayer. End quote.
The second view is that of those who regarded that as permissible on condition that what he recites in the second rak‘ah is not connected to what he recited in the first. An-Nawawi said in al-Majmoo‘ Sharh al-Muhadhdhab (3/392): If he recites according to one of the seven modes of recitation, it is mustahabb to complete the recitation in the same mode. But if he recites some of the verses in one mode and some in another of the seven modes, it is permissible, on condition that what he recites in the second rak‘ah is not connected to what he recited in the first. End quote.
Ibn al-Jazari said in an-Nashr fi’l-Qiraa’aat al-‘Ashr (1/18):
Al-Habr al-‘Allaamah Abu Zakariyya an-Nawawi said in his book at-Tibyaan: If the reciter begins in one of the seven modes of recitation, he should continue with that mode so long as the words are connected. If the section ends, then he may recite with another of the seven modes of recitation, but it is better to carry on in the same mode of recitation in that session. End quote.
To see this topic in the books of the Shaafa‘is, please see Asna’l-Mataalib fi Sharh Rawd at-Taalib (1/63); al-Iqnaa‘ fi Hill Alfaaz Abi Shujaa‘ (1/105); Mughni al-Muhtaaj ila Ma‘rifat Ma‘aani Alfaaz al-Minhaaj (1/153).
Ibn al-Jazari (may Allah have mercy on him) thought that this view was more likely to be correct when he said in an-Nashr fi’l-Qiraa’aat al-‘Ashr (1/19):
The correct view in our opinion is that the matter requires further discussion, so as to find a middle path. We say that if switching modes of recitation in a single verse would affect the meaning or render it incomprehensible, then in this case it is disallowed in the sense of being prohibited, such as when there is a sentence in which switching modes of recitation would change the case of a word from nominative to accusative, or vice versa, and could lead to there appearing to be two subjects or two objects in a single sentence (thus rendering it meaningless and contravening the rules of grammar). But if that is not the case, then we should differentiate between cases where the reciter claims that this is a mode of recitation or otherwise. If he recites it in this manner and claims that this is one of the modes of recitation, then it is not permissible because he is lying about that mode of recitation and it is confusing to people who have knowledge of recitation. If he is not claiming that this is a mode of recitation, rather it happened that he recited it this way, then it is permissible, valid and acceptable, and there is nothing wrong with it and it is not prohibited, even though we do not accept it from people who have knowledge of the different modes of recitation, because it is not acceptable for scholars to recite the Qur’an in the manner of people who have no knowledge, not because it is makrooh or haraam, because it is all from Allah and was brought down by the Trustworthy Spirit to the heart of the leader of the Messengers, to make it easy for the ummah and the people of this religion. If we had to require them all to recite according to one particular mode of recitation, it would be difficult for them to stick to one mode of recitation, and the aim of making things easy would be turned on its head. End quote.
The third view is that of those scholars who disallowed it. Ibn al-Jazari said in an-Nashr fi’l-Qiraa’aat al-‘Ashr (1/18):
Therefore some scholars regarded it as wrong for a reciter to mix the different modes of recitation with one another, whether in a Sunnah or obligatory prayer. Imam Abu’l-Hasan ‘Ali ibn Muhammad as-Sakhaawi said in his book Jamaal al-Qurraa’: Mixing these modes of recitation together is wrong. End quote.
It seems – and Allah knows best – that what is more correct with regard to this issue is to differentiate between the one who prays on his own, who may combine two or more recitations in one prayer, subject to the conditions mentioned by an-Nawawi and Ibn al-Jazari, and one who prays as an imam, leading people in prayer; in that case he should not do that, because reciting more than one mode of recitation in one rak‘ah may lead to confusion for the worshippers and may cause disputes and disagreements among them; in fact if he recites in a mode of recitation other than that which the people are used to, it may cause confusion.
It says in Fataawa al-Lajnah ad-Daa’imah (4/26), in the third question of fatwa no. 7339:
Is it permissible to recite Qur’an in prayer according to the recitation of Warsh, knowing that we usually recite according to the recitation of Hafs (that was transmitted) from ‘Aasim?
The answer was: reciting according to the mode of recitation of Warsh (that was transmitted) from Naafi‘ is valid in and of itself according to the scholars of recitation, but reciting in this mode of recitation for those who are not used to it, and are used to something else – such as the recitation that was transmitted from Hafs, for example – may cause confusion in the worshippers, so it should not be done for that reason. But if the one who is reciting according to this mode of recitation is praying on his own, then it is permissible, because there is no reason not to do that. End quote.
And Allah knows best.