Jesaja 56:4

"For thus saith Jehovah to the circumcised, Those who keep my Sabbaths, and decide for that in which I take pleasure, and take fast hold of my covenant; I give to them in my house and within my walls a memorial and a name better than sons and daughters: I give such a man an everlasting name, that shall not be cut off." The second condition after the sanctification of the Sabbath has reference to the regulation of life according to the revealed will of God; the third to fidelity with regard to the covenant of circumcision. יד also means a side, and hence a place (Deu 23:13); but in the passage before us, where ושׁם יד form a closely connected pair of words, to which וּמבּנות מבּנים is appended, it signifies the memorial, equivalent to מצּבת (2 Sam 18; 1:1-24:25; Sa1 15:12), as an index lifted up on high (Eze 21:24), which strikes the eye and arrests attention, pointing like a signpost to the person upon whom it is placed, like monumentum a monendo. They are assured that they will not be excluded from close fellowship with the church ("in my house and within my walls"), and also promised, as a superabundant compensation for the want of posterity, long life in the memory of future ages, by whom their long tried attachment to Jehovah and His people in circumstances of great temptation will not be forgotten.

After the exceedingly great and precious promises of gospel grace, typified by temporal deliverances, which we had in the foregoing chapter, we have here, I. A solemn charge given to us all to make conscience of our duty, as we hope to have the benefit of those promises (Isa 56:1, Isa 56:2). II. Great encouragement given to strangers that were wiling to come under the bonds of the covenant, assuring them of the blessings of the covenant (Isa 56:3-8). III. A high charge drawn up against the watchmen of Israel, that were careless and unfaithful in the discharge of their duty (Isa 56:9-12), which seems to be the beginning of a new sermon, by way of reproof and threatening, which is continued in the following chapters. And the word of God was intended for conviction, as well as for comfort and instruction in righteousness.

56:4 The Sabbath is a sign of the covenant (Exod 31:13-17).