Which four letters use idghām with ghunnah?Sākin Nūn & Tanwīn — Iẓhār, Idghām, Qalb and IkhfāʾLām, rāʾ, bāʾ, fāʾHamzah, hāʾ, ʿayn, ḥāʾTāʾ, dāl, ṭāʾ, ẓāʾYāʾ, nūn, mīm, wāw