But in the selection of the materials, we are pointed toward a deeper symbolism, by the injunction that in certain cases, at least, frankincense should be added to the offering. But this was not of man's food, neither was it, like the meal, and cakes, and oil, a product of man's labour. Its effect, naturally, was to give a grateful perfume to the sacrifice, that it might be, even in a physical sense, "an odour of a sweet smell." The symbolical meaning of incense, in which the frankincense was a chief ingredient, is very clearly intimated in Holy Scripture. It is suggested in David's prayer (Psalm cxli. 2): "Let my prayer be set forth as incense; the lifting up of my hands, like the evening oblation." So, in Luke i. 10, we read of the whole multitude of the people praying without the sanctuary, while the priest Zacharias was offering incense within. And, finally, in the Apocalypse, this is expressly declared to be the symbolical significance of incense; for we read (v. 8), that the four-and-twenty elders "fell down before the Lamb, having ... golden bowls full of incense, which are the prayers of the saints." So then, without doubt, we must understand it here. In that frankincense was to be added to the meal-offering, it is signified that this offering of the fruit of our labours to the Lord must ever be accompanied by prayer; and, further, that our prayers, thus offered in this daily consecration, are most pleasing to the Lord, even as the fragrance of sweet incense unto man. But if the frankincense, in itself, had thus a symbolical meaning, it is not unnatural to infer the same also with regard to other elements of the sacrifice. Nor is it, in view of the nature of the symbols, hard to discover what that should be. For inasmuch as that product of labour is selected for the offering, which is the food by which men live, we are reminded that this is to be the final aspect under which all the fruit of our labours is to be regarded; namely, as furnishing and supplying for the need of the many that which shall be bread to the soul. In the highest sense, indeed, this can only be said of Him who by His work became the Bread of Life for the world, who was at once "the Sower" and "the Corn of Wheat" cast into the ground; and yet, in a lower sense, it is true that the work of feeding the multitudes with the bread of life is the work of us all; and that in all our labours and engagements we are to keep this in mind as our supreme earthly object. Just as the products of human labour are most diverse, and yet all are capable of being exchanged in the market for bread for the hungry, so are we to use all the products of our labour with this end in view, that they may be offered to the Lord as cakes of fine meal for the spiritual sustenance of man.