FYI, it's "toeing" the line. It's an expression from track and field, where at the start of each race the competitors place the tip ("toe") of their foot on the start line when they're ready to run.
Similar to the expression "Up to scratch." In a boxing ring, there is a line in the ring that boxers must come to to begin the fight. To be "up to scratch" is to be ready and worthy of the fight, and from that, to be of acceptable quality or capability.