Of the two words so rendered is the Authorized Version, one,miphthan,,seems to mean sometimes a projecting beam or corbel. (Ezekiel 9:3; 10:4,18)
·noun Fig.: The place or point of entering or beginning, entrance; outset; as, the threshold of life...
Webster's Dictionary of the English Language
1) Heb. miphtan, probably a projecting beam at a higher point than the threshold proper (1 Sam. 5:4,...
Easton's Bible Dictionary