when they meet those who believe in muhammad they say we also believe in him. but when they meet one another in private they say have you got no sense that you disclose to them those things which allah has revealed to you so that they might bring them as a proof against you before your lord?
وإذا لقوا الذين آمنوا قالوا آمنا وإذا خلا بعضهم إلى بعض قالوا أتحدثونهم بما فتح الله عليكم ليحاجوكم به عند ربكم أفلا تعقلون