rush: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/sbin/rush - from package: rush

You may install the required package with command apt-get install {package}

Error in other languages:
rush: bevel nie gevind nie
rush: comandă negăsită
rush: comando não encontrado
rush: commande introuvable
rush: command not found
rush: käsku ei ole
rush: không tìm thấy lệnh
rush: komanda nerasta
rush: Kommando nicht gefunden.
rush: kommandot finns inte
rush: komut yok
rush: nie znaleziono polecenia
rush: níor aimsíodh an t-ordú
rush: no se encontró la orden
rush: no s'ha trobat l'ordre
rush: opdracht niet gevonden
rush: parancs nem található
rush: perintah tidak ditemukan
rush: príkaz nenájdený
rush: příkaz nenalezen
rush: команда не найдена
rush: командата не е открита
rush: 命令找不到
rush: コマンドが見つかりません