The Prophet ﷺ purchased food grains from a Jew on credit and mortgaged his iron armor to him.  

ذَكَرْنَا عِنْدَ إِبْرَاهِيمَ الرَّهْنَ فِي السَّلَمِ فَقَالَ حَدَّثَنِي الأَسْوَدُ عَنْ عَائِشَةَ ؓ أَنَّ النَّبِيَّ ﷺ اشْتَرَى طَعَامًا مِنْ يَهُودِيٍّ إِلَى أَجَلٍ وَرَهَنَهُ دِرْعًا مِنْ حَدِيدٍ  

Anas went to the Prophet ﷺ with barley bread having some dissolved fat on it. The Prophet ﷺ had mortgaged his armor to a Jew in Medina and took from him some barley for his family. Anas heard him saying, "The household of Muhammad did not possess even a single Sa of wheat or food grains for the evening meal, although he has nine wives to look after." (See Hadith No. 685)  

أَنَّهُ مَشَى إِلَى النَّبِيِّ ﷺ بِخُبْزِ شَعِيرٍ وَإِهَالَةٍ سَنِخَةٍ وَلَقَدْ رَهَنَ النَّبِيُّ ﷺ دِرْعًا لَهُ بِالْمَدِينَةِ عِنْدَ يَهُودِيٍّ وَأَخَذَ مِنْهُ شَعِيرًا لأَهْلِهِ وَلَقَدْ سَمِعْتُهُ يَقُولُ مَا أَمْسَى عِنْدَ آلِ مُحَمَّدٍ ﷺ صَاعُ بُرٍّ وَلاَ صَاعُ حَبٍّ وَإِنَّ عِنْدَهُ لَتِسْعَ نِسْوَةٍ