The precepts of the LORD are straightforward, making the heart rejoice (Psalm 19:9) refers to the order of Festivals, which has in it the sukkah, lulav, and festivals. As it is written in it, And you will rejoice in your festivals. (Deuteronomy 16:14). The commandment of the LORD is clear (Psalm 19:9) refers to the order of Holinesses, which clarifies the eyes to holy things. The judgements of the LORD are true and correct together (Psalm 19:10) refers to the order of Damages, which has in it all the judgements....ALTERNATIVE translation...: The ordinances of the Lord are upright, making the heart rejoice.
This is the order of Moed (appointed times), which includes Sukkot, Lulav, and festivals, as it is said in them (Deuteronomy 16:14), "and you shall rejoice in your festival." The commandments of the Lord are pure, enlightening the eyes to the holy. This is the order of Kedoshim (holiness), which illuminates the eyes towards the holy. The judgments of the Lord are true and righteous altogether. This is the order of Nezikin (damages), which includes all laws related to justice.