It is narrated from Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) that the letter of the Messenger of Allah (peace and blessings be upon him) reached the disbelievers, in which was written: "Come to a word that is equitable between us and you" to the end of the verse.
Hadith Referenceالمعجم الأوسط / باب الميم / 5436
Hadith Takhrij«أخرجه الطبراني فى «الكبير» برقم: 12103»