والبلاغة في المتكلم: ملكة يقتدر بها على تأليف كلام بليغ
Balagha in a speaker is a faculty enabling the composition of eloquent discourse.
A malaka is an established intellectual and linguistic capability, strengthened through practice. The expression yaqtadiru biha stresses an ability, not an isolated stroke of success.
Taʾlif kalam baligh means composing words so that the intended meaning is conveyed through fasih and contextually appropriate discourse. Fluent or grammatically correct Arabic alone does not exhaust this definition.