Regarding His saying: "The angels and the Spirit descend therein by the permission of their Lord," the Spirit is Gabriel, according to the Tafsir of al-Suddi. "Of every matter," meaning: with every matter, according to the Tafsir of al-Suddi.
قَوْلُهُ: ﴿تَنَزَّلُ الْمَلائِكَةُ وَالرُّوحُ فِيهَا بِإِذن رَبهم﴾ الرُّوحُ: جِبْرِيلُ؛ فِي تَفْسِيرِ السُّدِّيِّ ﴿من كل أَمر﴾ يَعْنِي: بِكُلِّ أَمْرٍ؛ فِي تَفْسِيرِ السّديّ