وَلَا تَتَّخِذُوا أَيْمَانَكُمْ دَخَلًا بَيْنَكُمْ فَتَزِلَّ قَدَمٌ بَعْدَ ثُبُوتِهَا وَتَذُوقُوا السُّوءَ بِمَا صَدَدتُّمْ عَن سَبِيلِ اللَّهِ وَلَكُمْ عَذَابٌ عَظِيمٌ

Do not make your oaths a means of [mutual] deceit among yourselves, lest feet should stumble after being steady and [lest] you suffer ill for barring from the way of Allah and face a great punishment.