Lam yafham is a jussive imperfect, whereas ifham is an imperative built on sukūn. Identical final marks do not make them the same grammatical category.
Opening interactive controls...
Common Error: Calling the Imperative Jussive
The Imperative: Definition, Formation, Hamza, and Building Signs
Lam yafham is a jussive imperfect, whereas ifham is an imperative built on sukūn. Identical final marks do not make them the same grammatical category.