…which things are symbolic. For these are the two covenants: the one from Mount Sinai which gives birth to bondage, which is Hagar—…but the Jerusalem above is free, which is the mother of us all. -Galatians 4: 24, 26

The first covenant for which Hagar stands, is the covenant of works, which is this: “There is my law, O man; if thou on thy side wilt engage to keep it, I on my side will engage that thou shalt live by keeping it. If thou wilt promise to obey my commands perfectly, wholly, fully, without a single flaw, I will carry thee to heaven. But mark Me, if thou violatest one command, if thou dost rebel against a single ordinance, I will destroy thee for ever.” …The Sarah covenant is the covenant of grace, not made with God and man, but made with God and Christ Jesus, which covenant is this: “Christ Jesus on His part engages to bear the penalty of all His people’s sins, to die, to pay their debts, to take their iniquities upon His shoulders; and the Father promises on His part that all for whom the Son doth die shall most assuredly be saved; that seeing they have evil hearts, He will put His law in their hearts, that they shall not depart from it, and that seeing they have sins, He will pass (these sins) by and not remember them any more for ever.”…There are no conditions whatever in the covenant of grace, or if there be conditions, the covenant gives them. The covenant gives faith, gives repentance, gives good works, gives salvation, as a purely gratuitous unconditional act; nor does our continuance in that covenant depend in the least degree on ourselves. The covenant was made by God with Christ, signed, sealed, and ratified, in all things ordered well.~ C.H. Spurgeon

https://www.blueletterbible.org/Comm/spurgeon_charles/sermons/0069.cfm