الْمُؤَيَّدِ بِسَاطِعِ حُجَجِهِ
Supported by the brilliance of his proofs.
Muʾayyad means supported or strengthened. Ḥujaj, the plural of ḥujjah, means proofs establishing a claim; sāṭiʿ suggests manifest brightness and clarity. The wording describes the strong evidential support of the Prophet's mission.
Proof versus assertion: Saying “this is true” merely states a claim. Providing a dependable ground for accepting it supplies evidence. Miracles and signs of revelation have traditionally been discussed as evidences of prophetic truthfulness; each particular claim requires its own substantiation.
Evidence supports considered conviction rather than unexamined imitation.