وَوَاضِحِ بَيِّنَاتِهِ
And by the clarity of his manifest signs.
Bayyināt is the plural of bayyinah: clear signs or evidence that illuminates a claim. Ḥujjah emphasizes the force of proof, while bayyinah emphasizes clarity and manifest indication. Their meanings overlap; they should not always be treated as wholly separate classes.
Example: Reliable testimony may support an account, and relevant, unambiguous testimony makes it clearer. In prophethood, manifest signs carry a specific religious significance and require appropriate evidence.
Good theological argument requires both evidence and a valid connection between that evidence and what it is supposed to establish. Irrelevant material is not strengthened reasoning.