Charles Ellicott Commentary Leviticus 19:24

"But in the fourth year all the fruit thereof shall be holy, for giving praise unto Jehovah." — Leviticus 19:24 (ASV)

But in the fourth year. —Like the second tithes, the fruits of the fourth year were taken up to Jerusalem, and there eaten by the owner, in company with the poor and needy whom he invited to the meal. The owner, however, was also allowed to redeem them. In this case, he had to add the fifth part of their value, take up the money to the holy city, and there spend it on a meal to which he invited the poor. The grapes of the vineyards within a distance of a day’s journey of Jerusalem had, however, to be taken up to decorate the streets of the holy city. Vineyards of the fourth year were exempt from the law laid down in Leviticus 19:9-10, as well as from the law of first-fruits, tithes, and second tithes.

Shall be holy to praise the Lord withal. —Better, shall be holy, a praise to the Lord, that is, either the fruits themselves, or their equivalent in money, shall be spent in the holy city, thus offering them at this sacrificial meal in praise to the Lord. (Compare Judges 9:27.)