Hast thou with him spread out the sky? - That is, wert thou employed with God in performing that vast work, that thou canst explain how it was done? Elihu here speaks of the sky as it appears, and as it is often spoken of, as an expanse or solid body spread out over our heads, and as sustained by some cause which is unknown. Sometimes in the Scriptures it is spoken of as a curtain (Notes, Isaiah 40:22); sometimes as a "firmament," or a solid body spread out (Septuagint, Genesis 1:6-7); sometimes as a fixture in which the stars are placed (Notes, Isaiah 34:4), and sometimes as a scroll that may be rolled up, or as a garment, Psalm 102:26. There is no reason to suppose that the true cause of the appearance of an expanse was understood at that time, but probably the prevailing impression was that the sky was solid and was a fixture in which the stars were held. Many of the ancients supposed that there were concentric spheres, which were transparent but solid, and that these spheres revolved around the earth carrying the heavenly bodies with them. In one of these spheres, they supposed, was the sun; in another the moon; in another the fixed stars; in another the planets; and it was the harmonious movement of these concentric and transparent orbs which it was supposed produced the "music of the spheres."
Which is strong - Firm, compact. Elihu evidently supposed that it was solid. It was so firm that it was self-sustained.
And as a molten looking-glass - As a mirror that is made by being fused or cast. The word "glass" is not in the original, the Hebrew denoting simply "seeing," or a "mirror" (ראי re'ı̂y). Mirrors were commonly made of plates of metal highly polished; see the notes at Isaiah 3:23; compare Wilkinson's Manners and Customs of the Ancient Egyptians, vol. iii. p. 365. Ancient mirrors were so highly polished that in some which have been discovered at Thebes the luster has been partially restored, though they have been buried for many centuries. There can be no doubt that the early apprehension in regard to the sky was, that it was a solid expanse, and that it is often so spoken of in the Bible. There is, however, no direct declaration that it is so, and whenever it is so spoken of, it is to be understood as popular language, as we speak still of the rising or setting of the sun, though we know that the language is not philosophically correct. The design of the Bible is not to teach science, but religion, and the speakers in the Bible were allowed to use the language of common life - just as scientific men in fact do now.

Hast thou with him spread out the sky - Wert thou with him when he made the expanse; fitted the weight to the winds; proportioned the aqueous to the terrene surface of the globe; the solar attraction to the quantum of vapours necessary; to be stored up in the clouds, in order to be occasionally deposited in fertilizing showers upon the earth? and then dost thou know how gravity and elasticity should be such essential properties of atmospheric air, that without them and their due proportions, we should neither have animal nor vegetable life?
Strong - as a molten looking-glass? - Like a molten mirror. The whole concave of heaven, in a clear day or brilliant night, being like a mass of polished metal, reflecting or transmitting innumerable images.

Hast thou with him spread out the sky, [which is] strong, [and] as a molten looking (o) glass?
(o) For the clearness.

Hast thou with him spread out the sky?.... Wast thou concerned with him at the first spreading out of the sky? wast thou an assistant to him in it? did he not spread it as a curtain or canopy about himself, without the help of another? verily he did; see Job 9:8, Isaiah 44:24;
which is strong: for though it seems a fluid and thin, is very firm and strong, as appears by what it bears, and are contained in it; and therefore is called "the firmament of his power", Psalm 150:1;
and as a molten looking glass; clear and transparent, like the looking glasses of the women, made of molten brass, Exodus 38:8; and firm and permanent (u); and a glass this is in which the glory of God, and his divine perfections, is to be seen; and is one of the wondrous works of God, made for the display of his own glory, and the benefit of men, Psalm 19:1. Or this may respect the spreading out a clear serene sky, and smoothing it after it has been covered and ruffled with storms and tempests; which is such a wonderful work of God, that man has no hand in.
(u) . Pindar. Nem. Ode 6.

with him--like as He does (Job 40:15).
spread out--given expanse to.
strong pieces--firm; whence the term "firmament" ("expansion," Genesis 1:6, Margin; Isaiah 44:24).
molten looking glass--image of the bright smiling sky. Mirrors were then formed of molten polished metal, not glass.

With him - Wast thou his assistant in spreading out the sky like a canopy over the earth? Strong - Which though it be very thin and transparent, yet is also firm and compact and steadfast. Looking glass - Made of brass and steel, as the manner then was. Smooth and polished, without the least flaw. In this, as in a glass, we may behold the glory of God and the wisdom of his handy - work.