Ṣaḥīḥ reporting in supplication and praising Allah the almighty

«اللَّهُمَّ إِنِّي أَعُوذُ بِكَ مِنَ الْمَأْثَمِ، وَالْمَغْرَمِ»
{وهو دعاء يُشرع قوله في التشهد الأخير قبل السلام}

Alllahuma 'inni 'aeudh bika min almathami, walmaghrami.

O Allah, I seek refuge in You from sin and from debt.

It is a supplication which to be said in last Tashahhud prior the salutations