Get yourself ready. Stand up and tell them everything that I command you. Do not be intimidated by them, or I will terrify you before them.
KJV
Thou therefore gird up thy loins, and arise, and speak unto them all that I command thee: be not dismayed at their faces, lest I confound thee before them.
ASV
Thou therefore gird up thy loins, and arise, and speak unto them all that I command thee: be not dismayed at them, lest I dismay thee before them.