Church Fathers on John 7:18

Our Lord delays His visit, in order to excite men’s attention, and goes up not the first day, but about the middle of the feast: Now about the midst of the feast Jesus went up into the temple, and taught. Those who had been searching for Him, when they saw Him thus suddenly appear would be more attentive to His teaching, both favorers and enemies; the one to admire and profit by it; the other to find an opportunity of laying hands on Him.

At the commencement of the feast, men would be attending more to the preachings of the festival itself; and afterwards would be better disposed to hear Christ.

The feast seems, as far as we can judge, to have lasted several days. And therefore it is said, “about the middle of the feast day:” i.e. when as many days of that feast had passed, as were to come. So that His assertion, I go not up yet to this feast day, (i.e. to the first or second day, as you would wish me,) was strictly fulfilled. For He went up afterwards, about the middle of the feast.