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In Temple times, the omer sacrifice was offered on the 16th of Nissan, right after the first festive day of Passover. This sacrifice was made of the first grain of the new harvest. It was only after the omer was offered that it became permissible to eat of the new crop. Even when the Temple was destroyed (and the omer could no longer be offered), the prohibition remained in place. All grain which begins growing after the 16th of Nissan is permissible only one year later, after the 16th of Nissan of the next year. This prohibition is referred to as ĥadash (“new”), and applies to the five grains: wheat, barley, spelt, oats, and rye.
The fruits produced by a tree in its first three years are called orla, and no one may eat them or benefit from them. In contrast, the fruits of the fourth year are holy, and there is a mitzva to eat them in a state of purity in Jerusalem. From the fifth year onwards, the fruits have no special status, and may be eaten once the requisite tithes have been given.
The prohibitions of orla and ĥadash are in force in the diaspora too. However, some maintain that ĥadash does not apply in the diaspora, and this opinion is commonly accepted.
There are two important takeaways from the mitzvot of ĥadash and orla. The first is self-control. We should not eat all our grains and fruits immediately, and we should not immediately use up anything else we acquire. The second is to dedicate the first of any crop to a higher cause. Therefore, one should give the first grains and fruits to God, and experience the occasion of eating a tree’s first permissible fruit in Jerusalem with joy and purity. Nowadays, however, without the Temple, the latter is impossible. Instead, we redeem the fruits of the fourth year by transferring their holiness onto a coin (or food worth at least a peruta), which we then respectfully set aside or dispose of.
