AL MAA-IDAH — Ayat 108

ذَلِكَ أَدْنَى أَن يَأْتُواْ بِالشَّهَادَةِ عَلَى وَجْهِهَا أَوْ يَخَافُواْ أَن تُرَدَّ أَيْمَانٌ بَعْدَ أَيْمَانِهِمْ وَاتَّقُوا اللّهَ وَاسْمَعُواْ وَاللّهُ لاَ يَهْدِي الْقَوْمَ الْفَاسِقِينَ

That is more likely that they will give testimony according to its [true] objective, or [at least] they would fear that [other] oaths might be taken after their oaths. And fear Allah and listen; and Allah does not guide the defiantly disobedient people.