'Understandest' in the Bible

What knowest thou, that we know not? what understandest thou, which is not in us?

Thou knowest my downsitting and mine uprising, thou understandest my thought afar off.

Lo, I will bring a nation upon you from far, O house of Israel, saith the LORD: it is a mighty nation, it is an ancient nation, a nation whose language thou knowest not, neither understandest what they say.