مَا كَانَ الْإِيقَافُ لِلْحِرْمَانِ، بَلْ لِلْفَحْصِ.
The suspension was not intended for deprivation, but for inspection.
If the listener firmly believes deprivation alone motivated the action, the response reverses that belief, resembling qaṣr al-qalb. If the listener attributes both deprivation and inspection and the speaker excludes the former, qaṣr al-ifrād becomes relevant.
The external form mā ... bal does not by itself settle the classification. The listener's belief and the precise proposition being corrected are decisive.