Assalamualaikum ustaz. During this pandemic, some mosques don’t allow people who didn’t bring their prayer mat to pray in the praying hall, but they are only allowed to pray at the veranda. So, they’ll pray there following the imam in the mosque. My question is, is it permissible because sometimes I see that the distance between the saf in the mosque and those at the veranda are very far away? Hope for an explanation. Thank you.
Waalaikumussalam wrt. wbt.,
Alhamdulillah, praise and gratitude to Allah SWT for His countless blessings for us all. Praise and salutations to our beloved Prophet Muhammad PBUH, his family, companions, and all those who follow his footsteps until the Final day.
We start with the statement of Allah SWT:
فَاتَّقُوا اللَّهَ مَا اسْتَطَعْتُمْ وَاسْمَعُوا وَأَطِيعُوا وَأَنفِقُوا خَيْرًا لِّأَنفُسِكُمْ ۗ وَمَن يُوقَ شُحَّ نَفْسِهِ فَأُولَٰئِكَ هُمُ الْمُفْلِحُونَ
“So, fear Allah as much as you are able and listen and obey and spend [in the way of Allah]; it is better for your selves. And whoever is protected from the stinginess of his soul – it is those who will be the successful.” 
Al-Sa’di stated in his commentary, Taisir al-Karim al-Rahman fi Tafsir Kalam al-Mannan , Allah SWT commanded His slaves to have taqwa for Him and obey all of His commandments and leave all of His prohibitions. Thus, this verse shows that all obligation that couldn’t be done by a slave is abrogated from him. Likewise, if the slave is capable to fulfil a part of the obligation but is incapable of other part of the obligation, then he should fulfil the obligation according to his capability and what he’s incapable of is abrogated from him as stated by the Prophet PBUH:
وَإِذَا أَمَرْتُكُمْ بِأَمْرٍ فَأْتُوا مِنْهُ مَا اسْتَطَعْتُمْ
“And when you are commanded to do anything, obey it as much as you can,” 
A veranda is an open but roofed and tiled/cemented space at the front or around the sides of a house.  Thus, we can define a mosque’s veranda as an open, roofed and tiled space that is usually built around the mosque. Usually, this space isn’t carpeted.
Condition to follow an imam for congregational prayer
Among the valid conditions of congregational prayer is the makmum must know the movements of the imam. Regarding this matter, al-Nawawi stated that it is conditioned that for a person following in a congregational prayer to be valid, the makmum must know every movement or action in the prayer of the imam, whether they are both – the imam and makmum – together in the mosque, outside the mosque, or one of them in or outside the mosque. This is agreed upon by scholars. Madhhab al-Syafi’I scholars stated the makmum’s knowing them may be from what he hears from the imam, hears from people following behind the imam, sees the movements of the imam or sees the movements of people who follow behind the imam and they cited the agreement of scholars regarding the permissibility of depending on one of these matters. 
The same is stated by al-Khatib al-Syirbini who set the condition that a makmum must know every action of the imam in prayer so that the makmum can follow him, whether by seeing the imam, seeing some of the saf – other makmum – hearing the imam’s voice or hearing the voice of the muballigh. 
Coming back to the presented question, if the imam and makmum are both in the mosque, following the imam it doesn’t matter how far away they are from each other and even if there are walls that can be walked through between them.  However, if the imam is in the mosque while makmum is outside the mosque, one of the conditions is that the distance between them mustn’t be too far. In this matter, scholars detailed three additional conditions:
- There must be anything hindering (barrier) the makmum from seeing the imam or other makmum that see the imam.
- The makmum can reach the imam without having to turn or deviate (away from the qibla).
- The distance between them mustn’t exceed 300 hasta.
The calculation of 300 hasta for the situation where the imam is in the mosque and makmum outside the mosque starts from the end of the mosque and not from the last saf in the mosque, which is the distance between the outside wall of the mosque and the place of the closest makmum to the imam outside the mosque, must not be more than 300 hasta. 
According to the above discussion and arguments, in our opinion, praying outside at the mosque’s veranda is permissible because it is still within the permissible distance of 300 hasta. Especially, when the 300 hasta calculation starts from the mosque’s wall and not the last saf in the mosque.
May Allah SWT grant us all a clear understanding in religion. Amin.