Luke 5:15

But so much the more went abroad the report concerning him: and great multitudes came together to hear, and to be healed of their infirmities.

The development in view here was the pressing unto him of such vast concourses of people with their incessant demands so much that it became physically impossible for Christ to continue. The foreknowledge of such a situation might have been one of the reasons underlying his charge that the leper should "tell no man." He apparently spread the word anyway; and, as a result, Christ found it necessary to depart, as related in the next verse.