وَلَا تَتَّخِذُوٓا۟ أَيْمَٰنَكُمْ دَخَلًۢا بَيْنَكُمْ فَتَزِلَّ قَدَمٌۢ بَعْدَ ثُبُوتِهَا وَتَذُوقُوا۟ ٱلسُّوٓءَ بِمَا صَدَدتُّمْ عَن سَبِيلِ ٱللَّهِ ۖ وَلَكُمْ عَذَابٌ عَظِيمٌ
Commentary:
The injunction contained in the previous verse has been repeated in the present one in order to bring home to Muslims the fact that although in principle it is not right to conclude treaties with dishonest motives, yet Muslims should particularly abstain from concluding such treaties, inasmuch as they are the bearers of the Divine Law and dishonest conduct on their part, even though it be in political affairs, will make men turn away from Islam. The words, or your foot will slip after it has been firmly established, mean that such conduct on the part of Muslims will weaken their power after it had become established in the earth. These words implied the great promise that although Muslims were being bitterly persecuted at Mecca by their opponents, yet the time was soon coming when God would establish their power on earth because such rules of conduct could only be laid down for a people who were destined to play a very prominent part in the politics of the world. The fulfilment of this prophecy under most unfavourable circumstances constitutes conclusive proof of the Quran being the revealed word of God.
Such conduct will weaken your power.