Surah An-Najm (The Stars), Verse 26

وَكَمْ مِّنْ مَّلَكٍ فِی السَّمٰوٰتِ لَا تُغْنِیْ شَفَاعَتُهُمْ شَیْـًٔا اِلَّا مِنْ بَعْدِ اَنْ یَّاْذَنَ اللّٰهُ لِمَنْ یَّشَآءُ وَیَرْضٰی ۟

Wa kam mim malakin fissamaawaati laa tughnee shafaa'atuhum shai'an illaa mim ba'di anyyaazanal laahu limany yashaaa'u wa yardaa

“How many-so-ever be the angels in the heavens, their intercession will avail nothing except after Allah has given leave for whom He pleases and that he is acceptable to Him.”

Quran 53:26 (Yusuf Ali Translation)