(ʿilm al-riwāya and āthār; rāwī; riwāya and āthār)
By ʿilm al-bāṭin (the science of the inward), we mean the knowledge of the acts that arise through the inward faculties. Likewise, by ʿilm al-ẓāhir (the science of the outward), we mean the knowledge that teaches the acts performed by the outward faculties. Allah says: "Allah has bestowed upon you His apparent (zāhir) and hidden (bāṭin) blessings" (cf. Luqmān 31:20).
The apparent blessing is the acts of obedience that Allah has enabled to manifest through the outward faculties. The hidden blessing is the spiritual state (ḥāl) that Allah has caused to arise in the qalb (the heart). Accordingly, the outward cannot exist without the inward, nor the inward without the outward. Allah says: ḥāl (spiritual state).