Why did the angel insist that Ya'akov let him go because the dawn was breaking?
(32,27) “And he (the angel) said: Let me go, for the dawn is breaking. And he (Ya’akov) said: I will not let you go unless you bless me.”
The gemora in Chullin 91b teaches that Ya’akov wondered why the angel was in such a rush to go, and asked him: Are you a thief or a kidnapper that you are afraid of the morning? The angel replied: I am an angel, and from the day that I was created my time to sing praises to Hashem did not arrive until now. The gemora concludes that this supports the teaching of R. Chananel in the name of Rav that there are three groups of ministering angels who sing praises to Hashem every day: one says “Holy”, the second says “Holy, Holy”, and the third says “Holy, Holy, Holy, is the Lord of Hosts”.
Tosafos there asks how this posuk supports the teaching of R. Chananel, because all that the posuk seems to prove is that the angels sing praises to Hashem. How does the gemora deduce that it also proves that there are different groups of angels? And we ourselves can further ask why the angel needed to state that he had never sang praises until now - even if he had sang before now nevertheless since the dawn was breaking it was time to sing again.
But it seems to me that we can answer all these problems very simply. Because we also have to ask why the angel needed to go somewhere else to sing praises to Hashem - surely Hashem is everywhere, and so the angel could have sung praises where he was without needing to ascend on high. The answer to this question is from the teaching of R. Chananel, that there are several groups of angels who praise Hashem each day, each group saying a different praise. Thus, since this angel had never sung until now he did not know to which group he belonged, and so he asked Ya’akov to let him go so that he could go and find out.
Thus, the posuk supports very well the teaching of R. Chananel that the angels are divided into groups and are not equal in how they praise Hashem.