"The Circle of the EarthTranslation and Meaning in Isaiah 40:22--Dennis Bratcher
The Hebrew word that is used in Isaiah 44:22 (חוּג, chug) does not at all imply a spherical earth. The root word only occurs in the Hebrew Bible once as a verb (Job 26:10). In nominal forms, the same root occurs four times, three as the noun חוּג (chug; Job 22:14, Prov 8:27, Isa 40:22), and once as the noun מְחוּגׇה (mechugah; Isa 44:13). This term refers to a "circle instrument," a device used to make a circle, what we call a compass.
http://www.crivoice.org/circle.html
You will find this site to be a more scholarly exegesis of Isaiah 40:22.
--Dave