Verse context: Al-An'am (6:5) and multiple other positions.
The two readings:
- Yukadhdhibun (tashdid — fa''ala form): Hafs and most readers in most positions
- Yakdhibun (takhfif — basic form): Some readers in some positions
Meaning difference:
- Yukadhdhibun (tashdid): They attribute falsehood to others — i.e., they deny the truth of what came to them, claiming it is a lie. More emphatic denial
- Yakdhibun (takhfif): They themselves are the liars — pointing to their own internal hypocrisy
General rule: Fa''ala (intensive) = attributing the action to another or intensive action. Fa'ala (simple) = the action comes from the doer himself.
Combined benefit: Both readings together describe the rejectors comprehensively: they are liars themselves and falsely accuse their messenger.
Question: What is the semantic difference between "yukadhdhibun" (tashdid) and "yakdhibun" (takhfif)?
Answer: Tashdid: they attribute falsehood to the messenger, claiming what he brought is a lie. Takhfif: they themselves are the liars, pointing to their own hypocrisy.