Musar su Salmi 139:16

The "cripple" described as sitting on the throne with three hundred disciples at his feet is an allusion to the Heavenly Spheres. There are ten emanations in each of the four worlds known as עולם האצילות, עולם הבריאה, עולם היצירה, עולם העשיה. Each emanation comprises ten sections totaling one hundred. There is a difference, however, between the divisions of the emanations in the עולם האצילות and those in the other three "worlds." The former are of infinite dimension; the latter have strict limitations, as explained in the Pardes Rimonim. We can detect another allusion here. It is known and accepted that a "spiritual day" comes into existence every day a person makes a contribution to "repairing" the damage caused to G–d's earth by Adam's sin. The Arizal derives this concept from Psalms 139,16: ימים יוצרו, "days were formed," i.e. that the positive deeds of man translate into tangible shapes, the "day". Our parable describes these deeds as the disciples. Individuals of average piety perform such "repairs" on fifty-four days a year, the days on which they engage in fasting. These fifty-four days are comprised of 40 plus the 11 eves of the New Moon, the tenth of Tevet, the seventeenth of Tamuz, and the ninth of Av. The fast commemorating the murder of Gedalyah and New Year's eve are included in the forty days mentioned. We are therefore left with another three-hundred days (the average year comprises 354 days). The disciples mentioned in the parable number 300, to tell us that these students engaged in "repairs," תקונים on the other 300 days of the year as well.