An Altar Of Earth

Quod autem additur ibi a Domino: Non facietis vobis deos argenteos et aureos, altare de terra facietis mihi. Altare enim de terra Deo facere est incarnationem Mediatoris sperare; tunc quippe a Deo nostrum munus accipitur, quando in hoc altari nostra humilitas, id est, super dominicae incarnationis fidem posuerit quidquid boni operatur; in altari ergo de terra oblationum munus offerimus, si actus nostros dominicae incarnationis fide solidamus. Sanctus Isidorus Hispalensis, Mysticorum Expositiones Sacramentorum Seu Quaestiones In Vetus Testamentum, In Exodum, Cap XXXII Source: Migne PL 83.304a-b

And there it is added by the Lord: 'You shall not make for yourselves gods of silver and gold, but an altar of earth you shall make for me.' 1 For the altar of earth for God is hope in the incarnation of the Mediator. Then certainly we have our gift from God, when our humility on this altar, that is, on the faith of the Lord's incarnation, shall place whatever good may be done. Therefore on this altar of earth, we offer our gifts of oblation, if we fortify our deeds in the faith of the Lord's incarnation. Saint Isidore of Seville, Expositions of Sacred Mysteries or Questions on the Old Testament, On Exodus, Chap 32 1 Exodus 20.23-24