Deeds are spoken of as if they were trees giving fruit that can be eaten. The fruit stands for the reward for doing good deeds. AT: "for they will receive their reward for their good deeds" or "for they will receive their reward for the good things they have done" (See: [[rc://en/ta/man/translate/figs-metaphor]])
The Hebrew text has these plural pronouns here, but they refer to any righteous person. Translators can choose to translate them as singular: "he will eat the fruit of his deeds."