and let them be ready for the third day; for on the third day Jehovah will come down before the eyes of all the people on mount Sinai.

and have been prepared for the third day; for on the third day doth Jehovah come down before the eyes of all the people, on mount Sinai.

And by the third day let them be ready: for on the third day the Lord will come down on Mount Sinai, before the eyes of all the people.

And let them be prepared on the third day. For on the third day, the Lord will descend, in the sight of all the people, over Mount Sinai.

Et sint parati in diem tertium: quoniam die tertio descendet Jehova coram oculis totius populi super montem Sinai.

And be ready against the third day,.... Not the third day of the month, but the third day from hence, this being the fourth, and the morrow the fifth, and the third day, the day following that, the sixth, on which day it is generally agreed by the Jews that the law was given; see Gill on Exodus 19:16.
for the third day the Lord will come down in the sight of all the people upon Mount Sinai; which must be understood, consistent with his omnipresence, and is only expressive of some visible display of his power, and of some sensible token of his presence to the people; he was now upon it in the pillar of cloud, but then he would appear in another manner, and descend in a thick cloud and fire, which all the people would see, though they could not see the similitude of anything in it.

In the sight of all the people - Though they should see no manner of similitude, yet they should see so much as would convince them, that God was among them of a truth. And so high was the top of Mount Sinai, that it is supposed not only the camp of Israel, but even the countries about might discern some extraordinary appearance of glory upon it.