In أَنْتُمْ عَابِدُونَ the following letter is ʿayn, while in لَكُمْ دِينُكُمْ it is dāl. Both require iẓhār shafawī: pronounce the mīm distinctly.
In دِينُكُمْ وَلِيَ, wāw also calls for a clear mīm; do not conceal it merely because both involve the lips.
Rule summary: mīm after sākin mīm → idghām; bāʾ → ikhfāʾ shafawī; other letters → iẓhār shafawī.
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Sākin mīm: compare two continuations
Al-Kāfirūn and An-Naṣr: Applied Madd, Idghām, Ghunnah and Waqf
In أَنْتُمْ عَابِدُونَ the following letter is ʿayn, while in لَكُمْ دِينُكُمْ it is dāl. Both require iẓhār shafawī: pronounce the mīm distinctly.
In دِينُكُمْ وَلِيَ, wāw also calls for a clear mīm; do not conceal it merely because both involve the lips.
Rule summary: mīm after sākin mīm → idghām; bāʾ → ikhfāʾ shafawī; other letters → iẓhār shafawī.