When those who disbelieved harbored in their hearts fierce zealotry (coming from egotism, tribalism, and feuding), the zealotry particular to the Age of Ignorance, God sent down His (gift of) inner peace and reassurance on His Messenger and on the believers, and bound them to the Word of faith, piety, and reverence for God. They were most worthy of it and entitled to it. And God has full knowledge of everything.