At the same time, when we refer to the hadiths that explain this verse, we see that lacking financial ability has been mentioned regarding the nafaqah and dowry, both of which the lack of financial ability doesn’t apply to in temporary marriage. So it can't be said that what is meant by marriage in the verse, covers both temporary and permanent marriage. The only thing this verse is speaking of, is permanent marriage.
Quranic verses must be interpreted and explained next to each other and as a whole, because some verses explain others. In this verse, continence has been proposed to those who can't afford neither temporary nor permanent marriage, and this isn't a reason for the impermissibility of mut’ah (temporary marriage), because in verse 24 of surah Nisa’, its permissibility has been pointed out: “…For the enjoyment you have had from them thereby, give them their dowries, by way of settlement, and there is no sin upon you in what you may agree upon after the settlement. Indeed Allah is all-knowing, all-wise.” Even those who are against mut’ah today never say that such a ruling never existed in Islam, what they say is that it indeed was permissible during the prophet (pbuh) and first khalifah’s time and it was the second khalifah that banned it or that it was revoked during the prophet’s (pbuh) time. Also, there are many hadiths in Sunni and Shia sources that disclose its permissibility.
What you have done is that you see not having financial ability (for nafaqah and dowry) that the verse speaks of as proof that it is only speaking of permanent marriage while: It isn't true that people can always afford temporary marriage, because although there is no responsibility for nafaqah in mut’ah, at the same time there is no marriage that takes place without any cost, because in all marriages, a mahr or dowry must be determined and paid to the wife, therefore, the verse is speaking of those who can't afford either of the two types of marriage, the difference being that in permanent marriage, they don’t have the nafaqah and dowry, and in temporary marriage, they don’t have the dowry.
1- The source of Islamic laws isn't just one verse, instead, when trying to derive a ruling, all verses that are somewhat related to that issue must be examined as a whole. Also, we must keep in mind that not all the details of worship have been covered in the Quran and have been transmitted to us through the prophet (pbuh) and imams in their hadiths, such as: the number of rak’ats of the daily prayers, the rituals of hajj, how to pay zakat, etc.
So, in Islam, there are more sources than just the Quran, meaning the traditions of the Prophet (pbuh) and imams that cover what hasn’t been in the Quran and our minds come short of understanding and discovering.
Therefore, just because a ruling can't be found in the Quran, or its details haven't been mentioned therein, it doesn’t mean that the ruling doesn’t exist in Islam, or its details are only limited to what the Quran has only mentioned. On the contrary, all verses and traditions must be seen as a whole.
2- Verse 33 of surah Nur tells those who can't afford the dowry and nafaqah (when the nafaqah applies): “Those who cannot afford marriage should be continent until Allah enriches them out of His grace.” If we pay attention, we will see that this verse speaks of marriage in an absolute manner, without specifically saying those who can't afford permanent marriage must be continent. Also, in hadithic terms, marriage encompasses more than just temporary marriage, in addition to the fact that it isn't true that all people can afford even temporary marriage, because even though there is no nafaqah in mut’ah (temporary marriage), there still is the mahr (dowry) that must be agreed upon and paid to the wife.
Therefore, the verse is about those who can't practice either of the two marriages, because in permanent marriage, there is the dowry and nafaqah that must be provided, and in temporary marriage, there is the dowry that must be paid for, so if there is anyone who can't afford both, the verse will apply to him, who tells them to be continent.
3- Even those who are against mut’ah today never say that such a ruling has never existed in Islam, they say that it was actually quite common during the prophet (pbuh) and first khalifah’s time, and it was the second khalifah who banned it or that it was revoked during the prophet’s (pbuh) time.
After mentioning these three points, we will list the reasoning from the Quran and tradition for the permissibility of mut’ah:
Verse 24 of surah Nisa reads; “…For the enjoyment you have had from them thereby, give them their dowries, by way of settlement, and there is no sin upon you in what you may agree upon after the settlement. Indeed Allah is all-knowing, all-wise.”
Imam Baqir (as) says about this verse: “This verse was revealed about mut’ah”.
Imam Sadiq (as) also says: “This verse is the reason for [the permissibility of] mut’ah”.
In some Sunni tafsirs too, this verse has been interpreted as speaking of mut’ah. In Tafsir Tabari, he narrates from Abi Nadrah from two different chains of narrators that I (Abi Nadrah) asked Ibn Abbas about mut’ah, he said: “Haven't you recited surah Nisa’?” I replied that I had. He then pointed to the verse “فما استمتعتم به...”.”
Qurtubi says: “All of the ulema say that what this verse is speaking of is mut’ah, which was practiced during the advent of Islam.”
Therefore, there is mut’ah in Islam, and in this verse, its mahr has been spoken of.
Also, there are numerous hadiths that see mut’ah as permissible, here we will point to one of them:
Imam Sadiq (as): “The ruling of mut’ah has been revealed in the Quran and it is the tradition of the prophet (pbuh).”
There are also numerous hadiths in Sunni sources of which we will bring one example:
In the chapter of “mut’ah marriage” of Sahih Muslim, Sahih Bukhari, Musannaf Abdul-Razzaq, Musannaf Ibn Abi Shaybah, Musnad Ahmad and Sunan Bayhaqi, Abdullah ibn Masoud has been narrated saying: “We would fight alongside the prophet (pbuh) and didn’t have wives, we contemplated castrating ourselves, the prophet forbade us and allowed us to temporarily marry women by paying them their mahr.”
All of these cases show that this ruling does indeed exist in Islam. For further information, see:
1- Temporary Marriage in the Quran and the lives of the Infallibles, Question 2965 (website: 3467).
2- The Abrogation of the Ruling of Temporary Marriage, Question 3352 (website: 3658).
 Tabatabai, Muhammad Husein, Farsi Translation of Al-Mizan, vol. 15, pg. 157.
 Nur:33 “و لْیَسْتَعْفِفِ الَّذِینَ لَا یجَدُونَ نِکاَحًا حَتىَ یُغْنِیهَمُ اللَّهُ مِن فَضْلِهِ”.
 To learn of all the viewpoints, refer to Al-Mizan (Farsi), vol. 15, pp. 460-493.
 Burujerdi, Muhammad Husein, Jame’ Ahadith Al-Shia, vol. 26, pg. 35.
 Ibid, pg. 36.
 Askari, Seyyed Murtada, Ezdevaje Movaqqat Dar Islam, pg. 16; Tafsir Tabari, vol. 15, pg. 9.
 Ibid, pg. 19.
 Jame’ Ahadith Al-Shia, vol. 26, pg. 40.
 Ezdevaje Movaqqat Dar Islam, pg. 22. For further information on all of the different cases that can be found in Sunni sources, refer to this book.