John Gill Commentary John 7:4

"For no man doeth anything in secret, and himself seeketh to be known openly. If thou doest these things, manifest thyself to the world." — John 7:4 (ASV)

For there is no man that does anything in secret
For so they reckoned his doing miracles in such a corner of the land, and in so obscure a place as Galilee:

and he himself seeks to be known openly ;
suggesting hereby, that Christ was an ambitious person, and sought popular applause, and honour and glory from men, when nothing was more foreign from him; see (John 5:41) (8:50) .

If you do these things ;
for they question whether the miracles he wrought were real; and suspected that they were deceptions of the sight, and delusions; or at least they questioned their being done by him; and rather thought that they were done by diabolical influence, by Beelzebub the prince of devils: but if they were real ones, they advise him, saying,

show yourself to the world ;
or do these openly, and in the presence of the great men of the world; the princes of it, the rulers of the people, the chief priests and sanhedrim; and before all the males of Israel; who at this feast would come up from all parts of the land, and are for their multitude called the world:

The reason of this their advice was, that if his miracles were real, and he was the person he would be thought to be, the doing of them before such, would gain him great credit and esteem; and if not, he might be detected by such numbers, and by men of such penetration as were among them.