The Holy Quran 43:86 — Surah Az-Zukhruf
Arabic text
وَلَا يَمْلِكُ ٱلَّذِينَ يَدْعُونَ مِن دُونِهِ ٱلشَّفَـٰعَةَ إِلَّا مَن شَهِدَ بِٱلْحَقِّ وَهُمْ يَعْلَمُونَ
Translation
Those (gods) that they (the Mushrikeen) worship besides Allaah have no power to intercede, except (that intercession will be allowed only) for the one who attests (is witness) to the truth (of Towheed) and (for) those who have knowledge (who are convinced about the truth of Towheed).
Tafsir (excerpt) — Tafsir Usmani
The right of intercession before Allah: that is, they can intercede only to the extent of bearing witness for someone who, as far as they know, uttered the word of Islam (the testimony of faith). Without the word of Islam they cannot say a single word of intercession on anyone's behalf.
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