Surah At-Taubah (The Repentance), Verse 4

اِلَّا الَّذِیْنَ عٰهَدْتُّمْ مِّنَ الْمُشْرِكِیْنَ ثُمَّ لَمْ یَنْقُصُوْكُمْ شَیْـًٔا وَّلَمْ یُظَاهِرُوْا عَلَیْكُمْ اَحَدًا فَاَتِمُّوْۤا اِلَیْهِمْ عَهْدَهُمْ اِلٰی مُدَّتِهِمْ اِنَّ اللّٰهَ یُحِبُّ الْمُتَّقِیْنَ ۟

Illal lazeena 'aahattum minal mushrikeena summa lam yanqusookum shai'anw-wa lam yuzaahiroo 'alaikum ahadan fa atimmooo ilaihim 'ahdahum ilaa muddatihim; innal laaha yuhibbul muttaqeen

“(But the treaties are) not dissolved with those Pagans with whom ye have entered into alliance and who have not subsequently failed you in aught, nor aided any one against you. So fulfil your engagements with them to the end of their term: for Allah loveth the righteous.”

Quran 9:4 (Yusuf Ali Translation)