Wrong:
cat * > www.buddhasutra.com_20211130.tar
See:
ls *

Right:
cat www.buddhasutra.com_20211130.tar.1 www.buddhasutra.com_20211130.tar.2 www.buddhasutra.com_20211130.tar.3 www.buddhasutra.com_20211130.tar.4 www.buddhasutra.com_20211130.tar.5 www.buddhasutra.com_20211130.tar.6 www.buddhasutra.com_20211130.tar.7 www.buddhasutra.com_20211130.tar.8 www.buddhasutra.com_20211130.tar.9 www.buddhasutra.com_20211130.tar.10 www.buddhasutra.com_20211130.tar.11 www.buddhasutra.com_20211130.tar.12 www.buddhasutra.com_20211130.tar.13 > www.buddhasutra.com_20211130.tar