The Guardian Angels.The Angels protect you.(Tafsir Ibn Kathir)
Allah said next,
For him (each person), there are angels in succession, before and behind him. They guard him by the command of Allah. Allah states that there are angels who take turns guarding each servant, some by night and some by day. These angels protect each person from harm and accidents. There are also angels who take turns recording the good and evil deeds, some angels do this by day and some by night.
There are two angels, one to the right and one to the left of each person, recording the deeds. The angel to the right records the good deeds, while the angel to the left records the evil deeds. There are also two angels that guard and protect each person, one from the back and one from in front. Therefore, there are four angels that surround each person by day and they are replaced by four others at night, two scribes and two guards. An authentic Hadith states, Angels take turns around you, some at night and some by day, and all of them assemble together at the time of the Fajr and `Asr prayers. Then those who have stayed with you throughout the night, ascend to Allah Who asks them, and He knows the answer better than they about you, “How have you left My servants?” They reply, “As we have found them praying, we have left them praying.” Imam Ahmad recorded that Abdullah said that the Messenger of Allah said, Verily, every one among you has his companion from the Jinn and his companion from the angels.”
They said, “And you too, O Allah’s Messenger!” He said, And I too, except that Allah has helped me against him, so he only orders me to do good. Muslim collected this Hadith. Ibn Abi Hatim narrated that Ibrahim said, “Allah revealed to a Prophet from among the Children of Israel, `Say to your nation: every people of a village or a house who used to obey Allah but changed their behavior to disobeying Him, then He will take away from them what they like and exchange it for what they dislike.” Ibrahim next said that this statement has proof in Allah’s Book, Verily, Allah will not change the (good) condition of a people as long as they do not change their state (of goodness) themselves. But when Allah wills a people’s punishment, there can be no turning it back, and they will find besides Him no protector.
Tafsir of Quran 13:11