The Messenger of Allah (p.
The Messenger of Allah (p.b.u.h.) was annoyed about it so that he threatened them with a probable intense heavenly punishment. So, as it is narrated in a tradition, in the extraordinary hot middays of summer, the Prophet (p.b.u.h.) performed the prayer (midday prayer) in congregation.
That prayer was the most grievous canonical prayers for the companions of the Prophet (p.b.u.h.) so that it happened that usually there stood no more than one or two lines of them behind the Prophet (p.b.u.h.) for midday prayer. In that circumstance, he (p.b.u.h.) said he had decided to burn the houses of those who did not participate in their prayer there. Then the verse was revealed and the importance of the noon prayer (in congregation) was emphasized thereby.
Commentary: The importance of the prescribed daily prayers, especially the midday prayer, is emphasized repeatedly in the verses of the Qur'an, for prayer is the most effective factor in the connection of man with Allah. As an instance, in the above verse it says: " Guard your prayers, and (especially) the middle prayer ..." The verse recommends to stand humbly, and truly obedient, before the Lord. "...
The weight of the authorities seems to favour interpreting it as the 'asr or the midday prayer, since it is mostly neglected and yet it is most necessary to remember Allah in the midst of the worldly engagements.
But in circumstances like that many of the obligations of prayer are diminished, for example: being to the direction of Qiblah, the performances of bowing and prostration in ordinary manner, and so on.