تَحْقِيقٌ لِلْمَسَائِلِ ... وَتَدْقِيقٌ لِلدَّلَائِلِ
Verification of the issues and close examination of their proofs.
Taḥqīq asks whether the issue is correctly framed and whether the evidence genuinely supports the proposition. Tadqīq examines the finer premises, inferential steps and possible objections.
Illustration: 'This statement is ancient because it is important' does not follow: importance alone does not establish antiquity. A careful analysis asks whether the premise and conclusion have the necessary connection.
Likewise, in theology the social appeal or rhetorical power of a claim must not be confused with the quality of its evidence.