Refuge from owing, and from what leads there
Asked in the prayer itself. When questioned about mentioning debt so often, he ﷺ explained why.
اللَّهُمَّ إِنِّي أَعُوذُ بِكَ مِنَ الْمَأْثَمِ وَالْمَغْرَمِ
Allāhumma innī aʿūdhu bika mina-l-ma'thami wa-l-maghram.
“O Allah, I seek refuge in You from sin and from debt.”
He was asked why he sought refuge from debt so often. He said that when a man is in debt he speaks and lies, and promises and breaks it.
The full narration
Narrated `Aisha:Allah's Messenger (ﷺ) 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 Messenger (ﷺ)! (I see) 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
Source
Ṣaḥīḥ al-Bukhārī · 2397
- Agreed upon as authentic (al-Bukhārī / Muslim)