Hakim asked (the Prophet): Messenger of Allah, a man comes to me and wants me to sell him something which is not in my possession. Should I buy it for him from the market? He replied: Do not sell what you do not possess. (Using translation from Abū Dāʾūd 3503)
قُلْتُ يَا رَسُولَ اللهِ يَأْتِينِي الرَّجُلُ يَسْأَلُنِي الْبَيْعَ لَيْسَ عِنْدِي مَا أَبِيعُهُ مِنْهُ ثُمَّ أَبِيعُهُ مِنَ السُّوقِ فَقَالَ لَا تَبِعْ مَا لَيْسَ عِنْدَكَ