Musar su Salmi 119:62

We find this to be the case in a number of other places in the Torah as well. Thus King David called the Holy One Blessed is He, ‘Midnight,’ literally….” [The idea, for the initiated, is that Nukba is called “the attribute of night,” and it comes out from behind the chest, which is the midpoint. Therefore David referred to the Holy One Blessed is He as “Midnight.” Thus the Zohar was very careful with its words, because He is literally Midnight. This is a great secret that should not be revealed except to the circumspect and the initiated.] The kingship of the House of David is called “the attribute of night,” therefore David used to rise at midnight, as it is stated, “I will arise at midnight to thank You for Your righteous laws.” Those who are capable of understanding on their own or who have received a tradition regarding these matters will grasp the meaning of the words “law” and “righteousness.” It is from here that judgments emanate. That is the allusion contained in the Sages’ principle that “the law of the kingship is the law” [Dina deMalchusa dina]. After this Rabbi Aba and Rabbi Yaakov came and kissed him….