Cyrill of Alexandria
The stones consecrated to God are not to be shaped with iron, as Christ is the chosen stone, the cornerstone, the genuine stone (1 Pet. 2:4, 6); He is untouched by sin, impervious to the assaults of the devil, and not torn between God and the world. Though He took on flesh, He remained entirely holy, undivided, through a profound union with humanity, being fully divine and fully human, never ‘divided,’ as the Apostle Paul clarifies (1 Cor. 1:13). Palladius. Therefore, the altar made from earth and the unhewn stones symbolize, as you've pointed out, Christ? Cyril. Precisely: for ‘the law is spiritual,’ as stated in Scripture (Rom. 7:14).