hash -r
echo ${BASH_CMDS[@]}

hash -p /usr/sbin/foo foo
hash -p /usr/local/bin/qux qux

echo ${!BASH_CMDS[@]}
echo ${BASH_CMDS[@]}

BASH_CMDS[blat]=/sbin/blat
BASH_CMDS[sh]=/bin/sh

hash

echo ${!BASH_CMDS[@]}
echo "${BASH_CMDS[@]}"