For nothing is hidden that will not be made manifest, nor is anything secret that will not be known and come to light.
The former paragraph began with an account of Christ's industry in preaching (Luk 8:1); this begins with an account of the people's industry in hearing, Luk 8:4. He went into every city, to preach; so they, one would think, should have contented themselves to hear him when he came to their own city (we know those that would); but there were those here that came...
Commenting on Luke 8:4-21
Take heed therefore how ye hear,.... That ye hear not in a careless and negligent manner, since what truths and doctrines ye now hear with the ear, are to be preached by you unto others: for whosoever hath; that is, hath knowledge of the doctrines of the Gospel, and hath gifts and abilities to preach them to others: to him shall be given; more knowledge...
Verse 17. , and Mr 4:22-25 (v) "nothing is secret"