251. How should I pray the four rak’aat voluntary prayers?

By Asma bint Shameem 

It’s Sunnah to pray the voluntary prayers as two by two. 

The Prophet sal Allaahu Alayhi wa sallam said:
“The (voluntary) prayers of the day and night are to be offered two by two.” 
(al-Tirmidh - saheeh by al-Albaani)

Uqbah ibn Hurayth said: 
“I said to Ibn ‘Umar: “What does two by two mean?” He said: “Saying the tasleem after each two rak’ahs.” 

Shaykh ibn al-‘Uthaymeen said: 
“The words two by two mean that you should not pray all four rak’ahs together, rather you should pray them two by two, because it is proven in Saheeh al-Bukhaari and Saheeh Muslim from Ibn ‘Umar that a man asked the Messenger of Allaah Sal Allaahu Alaiyhi wa Sallam:

“What do you think about the night prayers?” 

He said:
“Two by two, then if any one of you fears that dawn will come, let him pray one rak’ah and that will make what he has prayed odd-numbered for him.“

And Shaykh Ibn Baaz said: 
”What is prescribed is for the Muslim to offer the naafil prayers of the day and the night two by two, because the Prophet Sal Allaahu Alaiyhi wa Sallam said: 

“The night prayers are (to be offered) two by two” (saheeh – agreed upon). 

And according to a saheeh report he said: 
“The prayers of the night and the day are (to be offered) two by two.” Narrated by Imam Ahmad and the authors of al-Sunan with a saheeh isnaad.”
(Majmoo’ Fataawa al-Shaykh Ibn Baaz, 11/390)

So it’s better and preferable to pray the four rak’aat voluntary prayers as two by two. 

But if someone reads them all together with one salaam, the prayer is still valid. 

And Allaah knows best