Unix Builtin commands

Hi,
In unix ls command is found in /bin/ls. Similarly where can I find built-in commands like read, set, unset commands. I found in some couple of websites saying found in bash tool set. In unix everything is considered as a type of file with path.
Please can anyone tell me where is that Bash tool set found any path to find these built-in commands. Without clearing this doubt, I could not able to skip this built-in chapter.:b:

These commands are built into the shell executable itself (/bin/bash, /bin/ksh,...), so they do not exist as an independent filesystem object.

Don't take this statement to the letter. It is correct Unix tends to have more things associated to a path that most other operating systems but that's it. Hopefully, not everything has/is a path.

which name_of_command

Don't use "which". This command is only searching the PATH for the queried command. Only a builtin command can tell if another command is a builtin or not, this builtin is "type" with bash.

Didn't even think of that. Thanks