Musar su Salmi 86:1

Now let us discuss prayer. It is well known that Dovid HaMelech was known as the “singer of pleasant songs” and that he was a master of prayer. Therefore, as the Zohar teaches in Parashas Balak (195a), we must derive the proper order and content of our prayers from him. We find that Dovid sometimes counts himself among the “servants,” as it is written, “Look, as the eyes of servants look towards the hand of their master, etc.” (Tehillim 123:2). Sometimes among the poor, as it is written, “Hashem, incline Your ear and answer me, for I am poor and needy” (Tehillim 86:1). Sometimes among the pious, as it is written, “Of Dovid, guard my soul for I am pious” (ibid. 2). And sometimes he identifies himself with the holy ones who sacrifice their lives for the sanctification of Hashem’s name, as it is written, “Of Dovid; to You, Hashem, I lift up my soul, etc.” (Tehillim 25:1).