Obligatory word prolongation, heavy

The mechanic

A madd letter inside a word followed immediately by a letter carrying a shadda — a permanent sukun, so the prolongation never goes away. The mushaf prints the madd sign, then the shadda.

Where it occurs

Its condition, and how the mushaf marks it

ا و ي

• ٓU+0653
• ّU+0651

Length, as reported

Six harakat is what is reported, and is the well-known figure.

A place in the text

صِرَٰطَ ٱلَّذِينَ أَنۡعَمۡتَ عَلَيۡهِمۡ غَيۡرِ ٱلۡمَغۡضُوبِ عَلَيۡهِمۡ وَلَا ٱلضَّآلِّينَ

The marked spot was located in this ayah's own text at build time — Al-Fatihah 1:7.