Kitāb al-Ghayba > Philosophy and wisdom of Occultation
Hadith #3

فإن قيل: نحن نعترض قولكم في إمامته بغيبته بأن نقول إذا لم يمكنكم بيان وجه حسنها دل ذلك على بطلان القول بإمامته، لأنه لو صح لأمكنكم بيان وجه الحسن فيه.

If it is said: On the basis of his occultation, we question your belief in his Imamate. We say: If you cannot describe the wisdom of his disappearance, it indicates invalidity of your belief in his Imamate, because if it were valid, you should be able to describe the wisdom of his occultation.