Mark 3:30
He said this because they were saying, he has an impure spirit — the narrator's clarification grounds the blasphemy saying in the specific accusation of the Jerusalem scribes. The blasphemy against the Holy Spirit is not a general category of particularly bad sins but the specific act of attributing the Spirit's work to Satan. This is important for pastoral care: the person genuinely worried that they have committed the unforgivable sin has almost certainly not committed it — the concern itself demonstrates an openness to the Spirit's witness that the scribes' hardened accusation lacks. The unforgivable sin is the settled, persistent, deliberate demonization of the Spirit's activity.