al-Hafidh Emaad ad-Deen Isma’eel Ibn Katheer¹ [D.774A.H.] [رحمه الله] said in his Tafseer regarding the saying of Allaah [تعالى]:
﴿إِنَّ ٱللَّهَ وَمَلَٰٓئِكَتَهُۥ يُصَلُّونَ عَلَى ٱلنَّبِيِّۚ يَٰٓأَيُّهَا ٱلَّذِينَ ءَامَنُواْ صَلُّواْ عَلَيۡهِ وَسَلِّمُواْ تَسۡلِيمًا﴾
«Allaah sends His Salât [Graces, Honours, Blessings, Mercy, etc.] on the Prophet and also His Angels too [ask Allaah to bless and forgive him]. O you who believe! Send your Salât on [ask Allaah to bless] him, and [you should] send Salam upon him.» [Soorah Ahzab: 56]
Ibn Katheer [رحمه الله] said in his Tafseer:
❝The meaning of this Ayaah is: that Allaah [سبحانه و تعالى] informed His worshippers of the status of His slave and His Prophet with Him in the high gathering [Angels], in that Allaah [سبحانه و تعالى] praises the Prophet in the high gathering of the Angels that are close to Him.
Also, that the Angels pray for the Prophet [ﷺ], then Allaah [تعالى] ordered the people of the lower world to send as-Salat Wa Salam upon the Prophet, so that the praise of those of the high world and lower world are combined.❞
[Tafseer al-Qur’aan al-Atheem By al-Hafidh Ibn Katheer, (3/663)]