Translation:

46. Say: "I do admonish you on one point: that ye do stand up before Allah--(it may be) in pairs or (it may be) singly and reflect (within yourselves): your Companion is not possessed: he is no less than a Warner to you in face of a terrible Penalty."

Notes (Tafseer)

3857. A crowd mentality is not the best for the perception of the final spiritual truths. For these, it is necessary that each soul should commune within itself with earnest sincerity as before Allah: if it requires a Teacher, let it seek out one, or it may be that it wants the strengthening of the inner convictions that dawn on it, by the support of a sympathiser or friend. But careful and heart-felt reflection is necessary to appraise the higher Truths.

3858. Note that in verses 46, 47, 48, 49 and 50, arguments are suggested to the Prophet, by which he can convince any right-thinking man of his sincerity and truth. Here the argument is that he is not possessed or out of his mind. If he is different from ordinary men, it is because he has to give a warning of a terrible spiritual danger to the men whom he loves but who will not understand his Message.