Sunan Ibn Majah
2187
Sahih+3

It was narrated that Hakim bin Hizam said:"I said: 'O Messenger of Allah, a man is asking me to sell him something that I do not possess; Shall I sell it to him?' He said: 'Do not sell what is not with you

SahihAl-Albani
SahihMuhammad Fouad Abd al-Baqi