There is a medrish which says that the angels say kadosh all at the same time, for if one would start before the rest he would immediately be burnt up from the heat of his mouth. The Chofetz Chaim points out that there is no mention of the one who starts late. He says it must be that because of all the drive the angels have to sanctify Hashem’s Holy Name in the celestial sphere then there is only an issue of starting early; no one would start late. Angels act with zeal (zrizus) and there is a deep moral lesson (mussar haskel) we can take away from them.
Along these lines we find a very simple but profound understanding of this pasuk in the first interpretation of the Radak. The Radak says: “I heard that each saraf (angel) would call to each other and they would speak to each other in a motivating manner (derech ziruz). They would call each other ‘Kadosh, Kadosh’ like a person would say to his friend ‘sir, sir’ and they would announce ‘sanctify Hashem’s name together.’ Then they would say, ‘Holy is Hashem, Master of Legions, for He is the master of legions on high and the legions below. The whole world is filled with His glory, for He created everything and upon everything any logical thinking being shall glorify Him.’” (Click here and here for Hebrew text.)
There is a misnomer that zrizus refers to performing mitzvos quickly, with zeal, without wasting time. That is not entirely accurate. Zrizus is better defined as alacrity, doing something in a timely and optimal manner not too slow but not too fast, just at the right time in a manner which is thorough and accurate. This takes motivation, whether self-motivation or motivation by others to be sure it is done correctly.
In our case we find that the angels motivate each other to act in unison to praise Hashem. Angels are intelligent beings who are simply so close to Hashem that their fear of Hashem is so constant that they realize, as clear as day, that they should always be doing the right thing. It would seem, though, that with their zeal to want to do the right thing there are times when a false start might happen and consequences are paid. In order to motivate each other to start in unison, a call to attention before they start praising Hashem, they first call each other and announce that the time has come to praise Hashem.
If one looks closely at how this is done, the angels don’t say to each other ‘Michoel, Gavriel, Rephael get ready get set go!’ Rather, they speak to each other with respect, calling each other “Kadosh” (Holy). This seems to be an extra added motivator to act with zrizus and start in unison.
Angels are constantly self-motivated to serve Hashem with alacrity, through their fear of the awesomeness of Hashem’s Glory. Being that they are so close to Him, it is undeniable; but it would seem that added motivation is needed when praising Hashem to do it in unison, and the best motivation is positive reinforcement, treating one another with respect.
All the more so we can learn from the angels that when we want someone to do something for us or we want to motivate others to serve Hashem properly we should show proper respect to them. Refer to them as Mr., Mrs., Dr., Rabbi, or My Brother or My Sister, etc.; by speaking to them in a formal manner they will be more attentive and moved to listen to what you have to say.