Is it permissible to eat a chicken that was slaughtered, then stood up again and bled, then was slaughtered a second time?

If the slaughtering required by Islamic law has been completed, then the chicken is lawfully slaughtered. Its remaining alive or being slaughtered again does not affect the validity of the slaughter. Throwing it away after slaughtering is not permissible, as it constitutes a waste of money. However, if you withdraw your hand before completing the slaughter, this does not cause harm unless you have already severed some vital organs and then returned after an interval.