Sahih Bukhari Volume 3, Book 41, Hadith Number 582.

Narated By ‘Aisha : Allah’s Apostle used to invoke Allah in the prayer saying, “O Allah, I seek refuge with you from all sins, and from being in debt.” Someone said, O Allah’s Apostle! (I see you) very often you seek refuge with Allah from being in debt. He replied, “If a person is in debt, he tells lies when he speaks, and breaks his promises when he promises.”