Sayyiduna Abdullah bin Abbas (may Allah be pleased with them) narrates: The Prophet Muhammad (peace and blessings be upon him) said: "There is no validity in Islam for making alliances (as was customary in the time of ignorance), and whatever existed in the time of ignorance, Islam has only increased its severity (the narrator is in doubt, perhaps these are the words) has only increased its intensity."
Hadith Referenceصحیح ابن حبان / كتاب الأيمان / 4370
Hadith Gradingفضيلة الشيخ الإمام محمد ناصر الدين الألبانيصحيح بما بعده.فضيلة الشيخ العلّامة شُعيب الأرناؤوطسند صحيح على شرط مسلم