About the third hour - The Jews divided their days into twelve equal parts, or hours, beginning at sunrise and ending at sunset. This was, therefore about nine o'clock in the morning.
Standing idle in the market-place - A place where provisions are sold in towns. Of course, many resort to such places, and it would be the readiest place to meet persons and find employers. They were not, therefore, disposed to be idle, but were waiting in the proper place to find employers.

The third hour - Nine o'clock in the morning.
Market-place - Where laborers usually stood till they were hired. I have often seen laborers standing in the market places of large towns in these countries, waiting to be employed.

And he went out about the third hour,.... About nine o'clock in the morning,
and saw others standing idle in the market place: the place where labourers used to be hired: and may design the world, because a place full of people, and of great wickedness, for the whole world lies in it; a place of trade and traffic in worldly things, and likewise of worldly and carnal pleasure, and also of idleness. Now God's elect before calling, are in this place: they are natives of it, have their conversation according to it: here Christ came in person, and here he sends his ministers, his Gospel, to find them out, and by his Spirit and grace he calls them from hence; so that afterwards they are no more of it, though they are in it: but before conversion they belong to it, and their posture then is standing idle; being sluggish, and slothful in business, unwilling to work, and afraid of a little danger and trouble, sauntering away their time in carnal pleasures, and so clothed with rags, and in a starving, famishing condition: but Christ's eye is upon them; he observes, and takes notice of them in this disagreeable position and situation, and speaks of them in the following manner.

And he went out about the third hour--about nine o'clock, or after a fourth of the working day had expired: the day of twelve hours was reckoned from six to six.
and saw others standing idle in the market place--unemployed.

About the third hour. Nine o'clock. The hours were counted from six o'clock.