to drag after, to drag out, to involve, to delay, to implicate
拕 centers on pulling something along or drawing it out, whether physically dragging an object, delaying an action, or involving someone in a situation.
拕 combines 扌 (hand) with 它, which likely contributes the sound and may relate to the idea of dragging or pulling. The exact historical development is uncertain.
The hand radical 扌 beside 它 suggests a hand pulling something along. Imagine a hand dragging a heavy object that looks like the shape 它.
For タ, picture a hand dragging a tarpaulin: tar -> タ, and the hand pulls it across the ground.