i do think 'man command' should bring up the specific man page for this, so there is no need to search into the bash man. this works with most builtin shell commands. e.g. 'man ls' is a thing
`which ls` and `help ls` will show you, if it is similar on your system.
"man echo" on linux describes /usr/bin/echo "help echo" describes the builtin.
on the othe hand, "man command" on mac os x gives a huge manpage of builtins (still hard to search for the common word "command")