"On that Day, no intercession shall avail except for him whom the Most Merciful has given permission and for whom He has accepted a word" (yawmaʾidhin lā tanfaʿu ash-shafāʿatu illā man ʾadhina lahu ar-Raḥmānu wa raḍiya lahu qawlā). It means: the profession of Oneness (tawḥīd).
﴿يَوْمَئِذٍ لَا تَنْفَعُ الشَّفَاعَةُ إِلا مَنْ أَذِنَ لَهُ الرَّحْمَنُ وَرَضِيَ لَهُ قولا﴾ يَعْنِي: التَّوْحِيد.