Actually the original Hebrew word used does not in itself preclude the spherical.
Definition of the word "circle" in Isaiah 40:22
The original Hebrew word for circle is "khug." It meant "roundness" or "sphericity." So the word "khug" itself cannot be used to disprove that Isaiah was indeed describing a spherical earth.
As for pillars, God uses pillars in a figurative way.
Exodus 24:4
Moses then wrote down everything the LORD had said. He got up early the next morning and built an altar at the foot of the mountain and set up twelve stone pillars representing the twelve tribes of Israel.
Keep in mind also that Isaiah's authenticity as a true prophet would have been questioned if his statement had been perceived as contradicting the previous accepted inspired scriptures of prophets who spoke in God's name and whom they understood as describing the earth as resting on literal pillars.
Yet we have absolutely no evidence that the Hebrews viewed Isaiah's statement as uninspired or contradictory. Quite to the contrary, he was and still is considered a major prophet.
Since the Hebrews calmly accepted his statement about the earth then there are two possibilities. Either the concept he described was NOT foreign to the Hebrews. Or they had not understood the reference to pillars of the earth as literal but as being merely figurative.
Actually, if we were to consider the term "pillars" literally, then we would have to say that the Hebrews believed that heaven itself was held up by pillars:
Job 26:11
The pillars of the heavens quake, aghast at his rebuke.
Or that wisdom has literal pillars:
Proverbs 9:1
Wisdom has built her house; she has hewn out its seven pillars.
Or that the person referred to in Song of Solomon had pillars:
Song of Solomon 5:15
His legs are pillars of marble set on bases of pure gold. His appearance is like Lebanon, choice as its cedars.
Or that those of whom the Apostle Paul spoke about in his epistle to the Galatians were actually literal pillars:
Galatians 2:9
Galatians 2:9
James, Pete and John, those reputed to be pillars, gave me and Barnabas the right hand of fellowship when they recognized the grace given to me.
So it is in a figurative way and not a literal one that the Bible's reference to pillars of the earth is meant to be understood.
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