leave: 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/bin/leave - from package: leave

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

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