Whereupon are the foundations - Margin, "sockets." The Hebrew word (אדן 'eden) means "a basis," as of a column, or a pedestal; and then also the foundation of a building. The language here is evidently figurative, comparing the earth with an edifice. In building a house, the securing of a proper foundation is essential to its stability; and here God represents himself as rearing the earth on the most permanent and solid basis. The word is not used in the sense of sockets, as it is in the margin.
Fastened - Margin, "made to sink." The margin rather expresses the sense of the Hebrew word הטבעוּ hāṭâba‛û. It is rendered "sink" and "sunk" in Psalm 69:2, Psalm 69:14; Psalm 9:15; Lamentations 2:9; Jeremiah 38:6, Jeremiah 38:22; "drowned" in Exodus 15:4; and were settled in Proverbs 8:25. The word does not elsewhere occur in the Scriptures, and the prevailing sense is that of "sinking," or "settling down," and hence, to "impress" - as a seal "settles down" into wax. The reference here is to a foundation-stone that sinks or settles down into clay or mire until it becomes solid.
Or who laid the corner stone thereof - Still an allusion to a building. The cornerstone sustains the principal weight of an edifice, as the weight of two walls is concentrated on it, and hence, it is of such importance that it should be solid and firmly fixed. The question proposed for the solution of Job is, On what the earth is founded? On this question a great variety of opinions waft entertained by the ancients, and of course no correct solution could be given of the difficulty. It was not known that it was suspended and held in its place by the laws of gravitation. The meaning here is, that if Job could not solve this inquiry, he ought not to presume to sit in judgment on the government of God, and to suppose that he was qualified to judge of his secret counsels.

Whereupon are the foundations thereof fastened? - How does it continue to revolve in the immensity of space? What supports it? Has it foundations like a building, and is it fastened with a key-stone, to keep the mighty fabric in union?

Whereupon are the foundations thereof fastened?.... Or the pillars of it, as Ben Gersom interprets it; see Psalm 75:3; and which Aben Ezra understands of the mountains: but be they what they may, on what can they be fastened or sunk into, when the earth hangs on nothing, and there is nothing visible to support it, nothing but the mighty hand of God?
or who laid the corner stone thereof? which unites, cements, and keeps the fabric together, and is the ornament and beauty of it; but who can tell what that is? Aben Ezra interprets it of the point or centre of the earth.

foundations--not "sockets," as Margin.
fastened--literally, "made to sink," as a foundation-stone let down till it settles firmly in the clay (Job 26:7). Gravitation makes and keeps the earth a sphere.

Foundations - This strong and durable building hath no foundations but God's power, which hath marvelously established it upon itself. Cornerstone - By which the several walls are joined and fastened together, and in which, next to the foundations, the stability of a building consists. The sense is, who was it that built this goodly fabrick, and established it so firmly that it cannot be moved.