John Gill Commentary Psalms 17:6

"I have called upon thee, for thou wilt answer me, O God: Incline thine ear unto me, [and] hear my speech." — Psalms 17:6 (ASV)

I have called upon you
In prayer. This had been the constant practice of the psalmist, and he still continued in it;

for you wilt hear me, O God ;
God is a God hearing prayer; he is used to hear his people, and they have frequent experience of it, and they may be assured that whatsoever they ask according to his will, and in the name of Christ, he will hear; and such an assurance is a reason engaging the saints to a constant calling upon God, (Psalms 116:2) ; and such confidence of being always heard Christ had, (John 11:41John 11:42) ;

incline your ear unto me, [and hear] my speech ;
meaning his prayer, which he now directed to him in full assurance of being heard, and is as follows.