First: Definition and Ruling of Tajānos
Tajānos (similarity) is the relationship between two letters that share the same articulation point but differ in characteristics. For example: ṭāʼ, dāl, and tāʼ all share the same point of articulation but differ in their characteristics.
When two similar letters meet—where the first is non-voweled and the second is voweled—it may result in assimilation (idghām).
However, not every case of similarity necessitates assimilation. In the narration of Ḥafṣ from ʿĀṣim, assimilation due to similarity occurs in seven specific instances.¹
Second: Occurrences of Tajānos Assimilation in Hafs' Narration
1 - Assimilation of bāʼ into mīm, Allah Almighty say: – ﴿ٱرۡكَب مَّعَنَا﴾ [Hūd: 42], It is pronounced as: (irkam-maʿanā) with Complete assimilation meaning the first letter is merged into the second letter and it disappears completely(body and characteristics) , this assimilation is with Ghunnah 2 counts.
Note: Assimilation is classified based on completeness into two types:
- Complete assimilation: where the body and attributes of the assimilated letter are lost.
- Incomplete assimilation: where the body of the assimilated letter is lost but its attributes remain.²
2 - Assimilation of thāʼ into dhāl in one verse :– ﴿يَلۡهَثۚ ذَّٰلِكَ﴾ [Al-Aʿrāf: 176] It is read as : (yalha-dhdhālika) with Complete assimilation.
3 - Assimilation of dhāl into ẓāʼ in two verses: – ﴿إِذ ظَّلَمُوٓاْ﴾, ﴿إِذ ظَّلَمۡتُمۡ﴾ It is read as: (iẓ-ẓalamu...)(iẓ-ẓalamtum) with Complete assimilation.
4 - Assimilation of tāʼ into dāl in two verses: – ﴿أَثۡقَلَت دَّعَوَا﴾, ﴿أُجِيبَت دَّعۡوَتُكُمَا﴾ It is read as: (athqala-ddaʿawā), (ujība-ddaʿwatukumā)with Complete assimilation.
5 - Assimilation of dāl into tāʼ wherever it occurs throughout Quran for example:– ﴿قَد تَّبَيَّنَ﴾ It is read as (qat-tabayyana) with Complete assimilation.
6 - Assimilation of tāʼ into ṭāʼ wherever it occurs throughout Quran – ﴿فََٔامَنَت طَّآئِفَةٞ﴾ It is read as: (fāmanaṭ-ṭāʾifah)with Complete assimilation.
7 - Assimilation of ṭāʼ into tāʼ in four words: – ﴿بَسَطتَ﴾, ﴿فَرَّطتُمۡ﴾, ﴿أَحَطتُ﴾, ﴿فَرَّطتُ﴾ It is read with incomplete assimilation: the body of ṭāʼ disappears but its heaviness quality (tafkhīm) remains without qalqalah, so the reciter closes his mouth on Makhraj of non-vowelled ṭāʼ without Qalqalah and the he opens his mouth to pronounce the tāʼ ,while preserving heaviness Quality. The ṭāʼ wasn’t merged completely into tāʼ, because ṭāʼ is a strong letter which has Tafkhim and itbaq qualities , while tāʼ is a weak letter which has Tarqiq and separation qualities.