The Israeli military accused the Islamist movement Hamas on Friday of using the main hospital in Gaza as a shield for its tunnels and operational centres.
Edit: Replaced with Reuters link (Israel National News has a "mixed" factual reporting rating similar to Al Jazeera).
If they go in on foot, they're at much higher risk of being murdered by Hamas terrorists. On top of that, people like you will condemn them for going in and raiding a hospital.
Several soldiers on foot would be a LOT better for the hospital than a missile if that is really all they are looking for, although that doesn't seem to fit with what they've done so far