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Idgham Mithlayn

إدغام مثلين

“mithlayn”: the two alike; “idgham”: making one letter enter another

Lesson 9.1 · Module 9 · When two letters meet

Idgham Mithlayn (إدغام مثلين): two identical letters follow each other, the first with no vowel: it merges into the second, which is said doubled. Two identical letters, the first with no vowel: only one is said, doubled; never on a long-vowel letter. The Quran has 143 of them, in 49 surahs (Hafs reading).

What does Idgham Mithlayn mean?

Idgham Mithlayn (إدغام مثلين): “mithlayn”: the two alike; “idgham”: making one letter enter another

Two identical letters meet, the first with no vowel: it is not said on its own but merges into the second, said doubled. In the Mushaf, the first carries no sign and the second a shaddah. Never on a long-vowel letter.

Idgham Mithlayn: the 11 letters

Idgham Mithlayn in the Quran, letter by letter: computed by Tilawa on the text of the Madani Mushaf.
Letter Name In the Quran
ب bā 7
ت tā 8
د dāl 1
ذ dhāl 1
ر rā 3
ع ʿayn 2
ف fā 1
ك kāf 1
ل lām 98
ه hā 2
و wāw 19

In 69:28-29, the hā ending one verse meets the hā opening the next: it may be merged, or said with a short pause without taking a breath, the way teachers read first. Tilawa reads each verse in one go, stopping at its end: this case is not counted.

How to pronounce Idgham Mithlayn

Do not say the first letter: say the second, doubled, in a single movement.

The gesture
The tongue, or the lips, touch down once and hold the letter a little longer: that is the shaddah.
Avoid
Saying the letter twice, with a break or a bounce in between: only one should be heard, doubled.
The condition
The first must not be a long-vowel letter: a wāw or yā that lengthens the vowel before keeps its length, and both letters are said. A leen wāw (vowelless after a fathah) does merge.

Where the letters come from

Each point is shown on the mouth map, and each letter has its own page.

12 examples of Idgham Mithlayn in the Quran

Short surahs first. Tap ▶ to hear Idgham Mithlayn in its verse, recited by al-Husary.

Idgham Mithlayn: common mistakes

What is often heard, and how to fix it. The ▶ plays the right model, recited by al-Husary.

  1. Saying both letters: the first is not said; only one letter is heard, doubled.

    The right model · At-Talaq 65:2

  2. Bouncing on a bā or a dāl that merges: there is no qalqalah, the letter passes into the next.

    The right model · Al-Hujurat 49:12

  3. Merging a long-vowel letter into the same letter: the wāw that lengthens the vowel keeps its length, and the next wāw is said.

    The right model · Al-'Asr 103:3

  4. Keeping a leen wāw clear before a wāw: vowelless after a fathah, it merges.

    The right model · Al-Mutaffifin 83:3

  5. Pausing between the two words: the merge happens when joining, in one breath.

    The right model · Al-Kahf 18:24

Idgham Mithlayn and neighbouring rules

RuleWhenWhat happens
Idgham Mithlayn A letter with no vowel, then the same letter with a vowel, in one word or across two: all readers merge them. In the Mushaf, the first has no sign and the second carries a shaddah. Noon and meem have their own lesson (with the nasal sound). Two identical letters follow each other, the first with no vowel: it merges into the second, which is said doubled.
Idgham Mutajanisayn First letter with no vowel: among ت, د and ط; among ث, ذ and ظ; or from ب into م. A ṭā before a tā keeps its heaviness: the merger there is incomplete. A letter with no vowel, then a letter from the same place in the mouth: the first merges into the second.
Idgham Mutaqaribayn In Hafs, two cases: a lām with no vowel before a rā, and the qāf before the kāf (77:20). The Mushaf shows them: no sukoon on the first letter, a shaddah on the second. Except in 83:14, where a short pause (sakt) prevents the merger. A letter with no vowel, then a letter from a neighbouring place: the first merges into the second.

By ear: two words that sound alike

Two words that sound alike: one is read with Idgham Mithlayn, the other with Qalqalah. Listen for the difference.

Your turn: which rule?

By eye

The highlighted letters carry a rule. Which one?

  1. يَجْعَل لَّهُۥ

    yajʿallahū

    At-Talaq 65:4

  2. عَبَدتُّمْ

    ʿabattum

    Al-Kafirun 109:4

  3. قُل لَّا

    qullā

    Al-Hujurat 49:17

  4. قُل رَّبِّىٓ

    qurrabbī

    Al-Qasas 28:85

By ear

Listen, then choose the rule you hear. The word appears after you answer.

Practise: tajweed exercises with answers

Idgham Mithlayn in numbers

143times in the Quran

49surahs

Where to practise: the surahs of 20 verses or fewer with the most Idgham Mithlayn
SurahVersesIdgham Mithlayn
49. Al-Hujurat 18 3
65. At-Talaq 12 2
64. At-Taghabun 18 1
90. Al-Balad 20 1

Computed by Tilawa on the text of the Madani Mushaf (Hafs reading), from the letter that follows.

Frequently asked questions

What is Idgham Mithlayn in tajweed?

Two identical letters, the first with no vowel: only one is said, doubled; never on a long-vowel letter.

Which letters does Idgham Mithlayn apply to?

A letter with no vowel, then the same letter with a vowel, in one word or across two: all readers merge them. In the Mushaf, the first has no sign and the second carries a shaddah. Noon and meem have their own lesson (with the nasal sound). In the Quran, the most frequent is ل (lām): 98 times.

How many times does Idgham Mithlayn occur in the Quran?

143 times, in 49 surahs, as computed by Tilawa on the text of the Madani Mushaf (Hafs reading). Among the surahs of 20 verses or fewer, Al-Hujurat has the most: 3 in 18 verses.

Idgham Mithlayn or Idgham Mutajanisayn: what is the difference?

Idgham Mithlayn: two identical letters follow each other, the first with no vowel: it merges into the second, which is said doubled. Idgham Mutajanisayn: a letter with no vowel, then a letter from the same place in the mouth: the first merges into the second.

Idgham Mithlayn: how do I know I apply it correctly?

A rule is learned by ear: recite a surah out loud in the Tilawa app, which follows your recitation word by word and shows you where Idgham Mithlayn was missed or done wrong, with the word to replay in its verse.

Tilawa editorial team · Updated 2026-10-24 · Report an error