Psalms 105:8

We are here taught, in praising God, to look a great way back, and to give him the glory of what he did for his church in former ages, especially when it was in the founding and forming, which those in its latter ages enjoy the benefit of and therefore should give thanks for. Doubtless we may fetch as proper matter for praise from the histories of the gospels, and the acts of the apostles, which relate the birth of the Christian church, as the psalmist here does from the histories of Genesis and Exodus, which relate the birth of the Jewish church; and our histories greatly outshine theirs. Two things are here made the subject of praise: - I. God's promise to the patriarchs, that great promise that he would give to their seed the land of Canaan for an inheritance, which was a type of the promise of eternal life made in Christ to all believers. In all the marvellous works which God did for Israel he remembered his covenant (Psa 105:8) and he will remember it for ever; it is the word which he commanded to a thousand generations. See here the power of the promise; it is the word which he commanded and which will take effect. See the perpetuity of the promise; it is commanded to a thousand generations, and the entail of it shall not be cut off.

— Matthew Henry's Concise Commentary (public domain)