Midrash sur L’Exode 33:2

I will send an angel before thee … unto a land flowing with milk and honey … if I go in the midst of thee, even for a moment, I shall consume thee (Exod. 33:2, 5). How long is a moment? R. Samuel the son of Abba maintained: It is one fifty-eighth thousandth, six hundred and fiftieth part of an hour. That I may know what to do unto thee (ibid.). I will give them the Day of Atonement that it may atone for them. And the children of Israel stripped themselves of their ornaments (ibid., v. 6). (The ornaments) were the crowns which they had received at Mount Horeb. And they stripped themselves of them—unwillingly.