John Gill

I prevented the dawning of the morning, and cried,.... That is, he awoke and got up, and prayed, before the day broke, the morning looked forth, or the sun arose: he was early as well as earnest in his supplications to God; see Psa 5:3; as Christ, his antitype, rose early in the morning, a great while before day, and went out to a solitary place, and prayed, Mar 1:35; I hoped in thy word; which is a great encouragement to prayer, the grace of hope itself is, though a man can only put his mouth in the dust, if so be there may be hope; and especially when it is grounded on the word of promise, that God will hear and answer his people, when they call upon him in a time of trouble: and particularly hope in Christ, the essential Word, is a great encouragement; many encouraging arguments to prayer are taken from the person, office, advocacy, and mediation of Jesus Christ, Heb 4:14.