LII. (285) The law says, "A fire shall be kept burning on the altar which shall never be extinguished, but shall be kept burning for Ever."[Le 6:9.] I think with great reason and propriety; for, since the graces of God are everlasting, and unceasing, and uninterrupted, which we now enjoy day and night, and since the symbol of gratitude is the sacred flame, it is fitting that it should be kindled, and that it should remain unextinguished for ever. (286) And, perhaps, the lawgiver designed by this command to connect the old with the new sacrifices, and to unite the two by the duration and presence of the same fire by which all such sacrifices are consecrated, in order to demonstrate the fact that all perfect sacrifices consisted in thanksgiving, although, according to the diversity of the occasions on which they are offered, more victims are offered at one time and fewer at another. (287) But some are verbal symbols of things appreciable only by the intellect, and the mystical meaning which is concealed beneath them must be investigated by those who are eager for truth in accordance with the rules of allegory. The altar of God is the grateful soul of the wise man, being compounded of perfect numbers undivided and indivisible; for no part of virtue is useless. (288) On this soul the sacred fire is continually kept burning, preserved with care and unextinguishable. But the light of the mind is wisdom; as, on the contrary, the darkness of the soul is folly. For what the light discernible by the outward senses is to the eyes, that is knowledge to reason with a view to the contemplation of incorporeal things discernible only by the intellect, the light of which is continually shining and never extinguished.