And when Allah said: O Isa, I am going to terminate the period of your stay (on earth) and cause you to ascend unto Me and purify you of those who disbelieve and make those who follow you above those who disbelieve to the day of resurrection; then to Me shall be your return, so l will decide between you concerning that in which you differed.

And it does not beseem the believers that they should go forth all together; why should not then a company from every party from among them go forth that they may apply themselves to obtain understanding in religion, and that they may warn their people when they come back to them that they may be cautious?