Al-Baqarah 2:140 ام تقولون ان ابراهيم واسماعيل واسحاق ويعقوب والاسباط كانوا هودا او نصارى قل اانتم اعلم ام الله ومن اظلم ممن كتم شهادة عنده من الله وما الله بغافل عما تعملون ١٤٠

Or say you that Ibrâhîm (Abraham), Ismâ‘îl (Ishmael), Ishâq (Isaac), Ya‘qûb (Jacob) and Al-Asbât [the offspring of the twelve sons of Ya‘qûb (Jacob)] were Jews or Christians? Say, "Do you know better or does Allâh (knows better ... that they all were Muslims)? And who is more unjust than he who conceals the testimony [i.e. to believe in Prophet Muhammad صلى الله عليه وسلم when he comes, as is written in their Books. (See Verse 7:157)] he has from Allâh? And Allâh is not unaware of what you do."