Notes on the Bible, by Albert Barnes, [1834], at sacred-texts.com
Deuteronomy Chapter 15
The year of release is no doubt identical with the sabbatical year of the earlier legislation (Exo 23:10 ff, and Lev 25:2 ff), the command of the older legislation being here amplified. The release was probably for the year, not total and final, and had reference only to loans lent because of poverty (compare Deu 15:4, Deu 15:7). Yet even so the law was found to be too stringent for the avarice of the people, because it was one of those which the rabbis "made of none effect by their traditions."
Because it is called the Lord's release - Render, because proclamation has been made of the Lord's release. The verb is impersonal, and implies (compare Deu 31:10) that "the solemnity of the year of release" has been publicly announced.
The foreigner would not be bound by the restriction of the sabbatical year, and therefore would have no claim to its special remissions and privileges. He could earn his usual income in the seventh as in other years, and therefore is not exonerated from liability to discharge a debt anymore in the one than the others.
There is no inconsistency between this and Deu 15:11. The meaning seems simply to be, "Thou must release the debt for the year, except when there be no poor person concerned, a contingency which may happen, for the Lord shall greatly bless thee." The general object of these precepts, as also of the year of Jubilee and the laws respecting inheritance, is to prevent the total ruin of a needy person, and his disappearance from the families of Israel by the sale of his patrimony.
literally: "Beware that there be not in thy heart a word which is worthlessness" (compare Deu 13:13 note).
Thou shalt furnish him liberally - The verb in the Hebrew is remarkable. It means "thou shalt lay on his neck," "adorn his neck with thy gifts."
The commands here are repeated from Exo 21:2-6, with amplifications relative to the maidservant Deu 15:12 and to the making (Deu 15:13 ff) liberal provision for launching the freedman on an independent course of life. The release of the servant is connected with the sabbatical principle though not with the sabbatical year. It is noteworthy also that the prospect of a gift of this sort, the amount of which was left to the master's discretion, would be likely to encourage diligence and faithfulness during the years of servitude.
He hath been worth a double hired servant to thee, in serving thee six years - "i. e." such a servant has earned twice as much as a common hired laborer would have done in the same time.
Compare Exo 13:11 ff. The directions of the preceding legislation (see Num 18:15 ff) are here assumed, with the injunction added, that the animals thus set apart to God Deu 15:19 were not to be used by their owners for their earthly purposes. It is further allowed that firstborn animals which had a blemish should be regarded as exceptions, and instead of being given to God might be used as food Deu 15:21-22. The application of the firstborn of cattle is here directed as in Deu 12:6, Deu 12:17; Deu 14:23 : they are to be consumed in the sacred Feasts at the sanctuary.