It is written:
“It is He who sits above the circle of the earth, And its inhabitants are like grasshoppers, Who stretches out the heavens like a curtain, And spreads them out like a tent to dwell in.” (Isaiah 40:22)
Some in our day and age contend that the Earth is flat. Among these people, there are those who claim that the Bible teaches the idea of a flat earth.
However, a careful study of Isaiah 40:22 makes it clear that the Bible writers deny flat-earth speculation.
“Many Christian authors claim that the Hebrew word for circle here (hug) refers to the earth being a globe. Notice the parallel structure here. The first half of the verse describes the roundness of the earth, followed by a simile about the inhabitants of the earth. The second half of the verse describes the stretching of the heavens (probably a reference to what God did on day two of the creation week), followed by a simile about the heavens. Everyone agrees that the heavens appear to have curvature, whether a dome or a sphere around the earth…“The Hebrew word hug is used only two other times in the Old Testament. One appearance is in Proverbs 8: 27: When he established the heavens, I was there; when he drew a circle on the face of the deep. (The “I” here is a personification of wisdom.) The only other time that this word appears in the Old Testament is Job 22: 14: Thick clouds veil him, so that he does not see, and he walks on the vault of heaven. Note that in the King James Version, this word is rendered “circuit.” Also note that if one goes with “vault” as a good translation of hug as the English Standard Version does, a vault is a two-dimensional surface that is curved in a third dimension. This is an apt description of the surface of a sphere, as a vault is generally hemispherical. No wonder flat-earthers generally don’t mention Job 22: 14, because that might lead to the conclusion that Isaiah 40: 22 really does describe the earth being spherical. The Hebrew word hug derives from the word chuwg, which appears only once in the Old Testament, in Job 26: 10: He has inscribed a circle on the face of the waters at the boundary between light and darkness. This obviously is a reference to the creation of light on day one. On a spherical earth, the division between night and day is always a circle. Therefore, this verse appears to be consistent with a spherical earth, too.” (Dr. Danny Faulkner, Falling Flat: A Refutation of Flat Earth Claims, 270-271 (Kindle Edition); Green Forest, AR; Master Books)
Our flat-Earth friends contend that if Isaiah wanted to suggest a spherical Earth, he would have chosen a different Hebrew word. However, Faulkner documents:
“But, more importantly, they say that the Hebrew word hug must mean a circle, not a globe. Their evidence is that the prophet Isaiah used a word meaning “ball” elsewhere, so if Isaiah had meant to convey that the earth was spherical, he would have used this word in Isaiah 40: 22. The verse in question is Isaiah 22: 18: And whirl you around and around, and throw you like a ball into a wide land. There you shall die, and there shall be your glorious chariots, you shame of your master’s house. The Hebrew word translated “ball” here is kaddur. It occurs two other times in the Old Testament. One occurrence is in Isaiah 29: 3: And I will encamp against you all around, and will besiege you with towers and I will raise siegeworks against you. Obviously, the meaning here isn’t a ball, but a circle. The other time kaddur appears is Ezekiel 24: 5: Take the choicest one of the flock; pile the logs under it; boil it well; seethe also its bones in it. Here, kaddur is translated “pile.” Note that in the English Standard Version, a footnote on the word “logs” indicates that the Hebrew word used there literally means “bones.” The important thing to recognize is that the Hebrew word kaddur can be translated several ways, such as ball, circle, and a pile, or heap. Therefore, the insistence that kaddur is the appropriate Hebrew word for “ball” is unwarranted. In English, most people don’t think of the word “round” to be restricted to two dimensions. Many people speak of the earth being round when they mean that the earth is a globe. But flat-earthers speak of the earth being round, too. That is, roundness applies to either a circle or a sphere (topologically, a sphere is merely a three-dimensional circle).” (Dr. Danny Faulkner, Falling Flat: A Refutation of Flat Earth Claims, 271-272 (Kindle Edition); Green Forest, AR; Master Books)
Despite his defense of the passage, Faulkner believes that Isaiah 40:22 is not conclusive in proving the rotundity of the Earth.
However, other scholars disagree.
For example:
“THE SPHERICITY OF EARTH: For a long time people used to think that the earth is flat. It was not considered safe for ships to venture beyond the pillars of Hercules (at the entrance to the straits of Gibraltar) into the Atlantic ocean because at the boundary of the flat earth the ship would fall into the abyss. However, Bible teaches no such error. In Isaiah 40: 22 the “circle of the earth” is mentioned in connection with its shape. The word KHUG used in Hebrew refers to a spherical body. We infer the same from the Lord Jesus when He spoke in Luke 17: 34 to 36 about His second coming. This coming was to be instantaneous yet He said, “I tell you, in that night there shall be two men in bed, the one shall be taken and the other shall be left. Two women shall be grinding together; the one shall be taken the other left. Two men shall be in the field; the one shall be taken and the other left”. (Luke 17: 34-36) The Lord Jesus said that He will come in a moment yet three activities corresponding roughly with morning noon and night have been shown to take place at the same moment. Obviously, the reference is to the spherical earth on which alone simultaneity of such events is possible.” (Dr. Johnson C. Philip & Dr. Saneesh Cherian, Bible And Modern Science (Christian Apologetics), 562-574 (Kindle Edition))
The Bible denies flat-earth cosmology.