The following is my understanding of the Degel Machane Ephraim on Parshas Bamidmar, writing in the name of his grandfather, the Baal Shem Tov. (Incidentally, this parsha contains the words “Degel Machane Ephraim”.)
The last posuk in Bamidbar (4:20) says:וְלֹא-יָבֹאוּ לִרְאוֹת כְּבַלַּע אֶת-הַקֹּדֶשׁ וָמֵתוּ And you should not go in to see as they cover the holy, or they will die.
At times, one will go to see a tzadik, in order to learn from his actions, however, the tzadik will be in a state of katnus (doing thing he normally wouldn’t, due of his lowered state), and this person will learn things improperly from him. This happened once, when someone saw Reb Nachman Horedenker drinking coffee, while wearing his talis and tefilin, and this individual proceeded to do the same thing, thinking this is a proper way to act.
This posuk alludes this important lesson to us, in the: And you should not go in to see – and learn improperly, as they cover the holy – meaning while the tzadik is in a state of katnus, or they will die - meaning you will fall from your current level.
I could just imagine the scene. A fellow comes into shul, sees some people drinking coffee before davening and thinks to himself that these guys don’t know what they are doing. He puts on his talis and tefilin, then makes himself a coffee and smugly tells his friends that an erlicher yid should really drink coffee like this – only while wearing talis and tefilin.
Similarly, there are those who daven Shachris after the zman and sometimes even after chatzos, because they saw a great tzadik davening late. Some of them actually think they are extra frum because of this and look askance at those who are particular to daven bizmanah. The difference is the tzadik didn’t roll out of bed at the crack of noon. (This is not the place for the discussion of tzadikim davening late, but they have reasons for this and don’t want the general public to copy them. One of the great tzadikim, who davened Shachris after the zman often, said that every day he intends to daven at 8:30AM, however, for reasons beyond his control he usually is not able to daven at his intended time. It says one sin causes another sin, so if this is the only sin one can find in a tzadik, it must not be a sin.)