Sura al-Māʾidah 5:108

ذَٰلِكَ أَدْنَىٰٓ أَن يَأْتُوا۟ بِٱلشَّهَٰدَةِ عَلَىٰ وَجْهِهَآ أَوْ يَخَافُوٓا۟ أَن تُرَدَّ أَيْمَٰنٌۢ بَعْدَ أَيْمَٰنِهِمْ وَٱتَّقُوا۟ ٱللَّـهَ وَٱسْمَعُوا۟ وَٱللَّـهُ لَا يَهْدِى ٱلْقَوْمَ ٱلْفَٰسِقِينَ

dhālika adnā an yaʾtū bil-shahādati ʿalā wajhihā aw yakhāfū an turadda aymānun baʿda aymānihim wattaqū allāha wa-ismaʿū wallāhu lā yahdī l-qawma l-fāsiqīna

That is most suitable: that they may give the evidence in its true nature and shape, or else they would fear that other oaths would be taken after their oaths. But fear Allah, and listen (to His counsel): for Allah guideth not a rebellious people: