How to quickly create an SCP account with limitted permissions?


im having a linux (redhat) vps with root ssh access. i want to quickly create a new account for scp connections.

example i want to temporarilly give the credentials to some person which i dont know good. And i want him to have only access to folder lets say /home/peter ? and dont allow him to to consume more than 20gb of disk space or anyhow breach the security of the linux system.

is there any quick secure way to allow such scp access?