Sahih Bukhari, Hadith: Q2404, (17) Chapter. It is permissible to lend money for a fixed time or sell on credit for a fixed time.

صحيح البخاري

Sahih Bukhari

كتاب الاستقراض

The Book of Loans, Freezing of Property, and Bankruptcy

باب إذا أقرضه إلى أجل مسمى أو أجله فى البيع:

(17) Chapter. It is permissible to lend money for a fixed time or sell on credit for a fixed time.