Isaiah 51:1

Observe, 1. How the people of God are here described, to whom the word of this consolation is sent and who are called upon to hearken to it, Isa 51:1. They are such as follow after righteousness, such as are very desirous and solicitous both to be justified and to be sanctified, are pressing hard after this, to have the favour of God restored to them and the image of God renewed on them. These are those that seek the Lord, for it is only in the say of righteousness that we can seek him with any hope of finding him. 2. How they are here directed to look back to their original, and the smallness of their beginning: "Look unto the rock whence you were hewn" (the idolatrous family in Ur of the Chaldees, out of which Abraham was taken, the generation of slaves which the heads and fathers of their tribes were in Egypt); "look unto the hole of the pit out of which you were digged, as clay, when God formed you into a people." Note, It is good for those that are privileged by a new birth to consider what they were by their first birth, how they were conceived in iniquity and shapen in sin. That which is born of the flesh is flesh.

— Matthew Henry's Concise Commentary (public domain)