Taking usury is forbidden because it is what a person obtains by exploiting the needs of others.

  وَأَحَلَّ اللَّهُ الْبَيْعَ وَحَرَّمَ الرِّبَا ۚ

(But Allah has permitted trade and has forbidden interest.) (Al-Baqara: 275)

Albeit of that, the Jews deal with interest.

(… وَأَكْلِهِمْ أَمْوَالَ النَّاسِ بِالْبَاطِلِ …) (…, and their consuming of the people’s wealth unjustly …): Either through theft or through bribery and fraud, all these methods of fraud to consume money were used by the Jews, so they were forbidden from good things that used to be permissible for them.

So that, Allah (swt) has made good things lawful for them, but by their wrong doings and consuming usury and people’s wealth unjustly, He (swt) forbade them from good things that were made lawful for them.

(  وَأَعْتَدْنَا لِلْكَافِرِينَ مِنْهُمْ عَذَابًا أَلِيمًا … ) (And we have prepared for the disbelievers among them a painful punishment …): In addition to making unlawful for them certain good foods, Allah (swt) prepared for them a severe punishment.