gush out, spurt
迸 centers on a sudden, forceful outward release: liquid gushing or spurting out under pressure.
迸 combines 辶 (movement) with 并, which likely contributes the sound and the idea of bursting forth. The exact historical development of the inner component is uncertain.
The movement radical 辶 surrounds 并, like liquid bursting out of a container and flowing away. Picture a pipe suddenly spurting water onto the path.
For ホウ, imagine a hose suddenly bursting and water gushing out with a loud 'hoe!' sound: hoe -> ホウ, as the water spurts everywhere.