Sand shield blocks supersonic projectile

Right before his eyes, a kunai was rushing towards him with supersonic speed. It’s speed was pretty much equal to that of a wind or lightning release.
If Gaara had been a normal shinobi, then his skull would’ve been pierced before he noticed it, and he’d have died.
But, Gaara’s sand surged out of his gourd and casually deflected the kunai. His sand shield. It was an absolute defence concerned only with protecting him, one that wasn’t even connected to his own will.

-Gaara Hiden