stash: 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/lib/staden/bin/stash - from package: staden

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

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