I. The preface, Our Father who art in heaven. Before we come to our business, there must be a solemn address to him with whom our business lies; Our Father. Intimating, that we must pray, not only alone and for ourselves, but with and for others; for we are members one of another, and are called into fellowship with each other. We are here taught to whom to pray, to God only, and not to saints and angels, for they are ignorant of us, are not to have the high honours we give in prayer, nor can give favours we expect. We are taught how to address ourselves to God, and what title to give him, that which speaks him rather beneficent than magnificent, for we are to come boldly to the throne of grace.
1. We must address ourselves to him as our Father, and must call him so. He is a common Father to all mankind by creation, Mal 2:10,Ac 17:28. He is in a special manner a Father to the saints, by adoption and regeneration (Eph 1:5,Ga 4:6); and an unspeakable privilege it is. Thus we must eye him in prayer, keep up good thoughts of him, such as are encouraging and not affrighting; nothing more pleasing to God, nor pleasant to ourselves, than to call God Father. Christ in prayer mostly called God Father. If he be our Father, he will pity us under our weaknesses and infirmities (Ps 103:13), will spare us (Mal 3:17), will make the best of our performances, though very defective, will deny us nothing that is good for us, Lu 11:11-13. We have access with boldness to him, as to a father, and have an advocate with the Father, and the Spirit of adoption. When we come repenting of our sins, we must eye God as a Father, as the prodigal did (Lu 15:18,Jer 3:19); when we come begging for grace, and peace, and the inheritance and blessing of sons, it is an encouragement that we come to God, not as an unreconciled, avenging Judge, but as a loving, gracious, reconciled Father in Christ, Jer 3:4.
2. As our Father in heaven: so in heaven as to be every where else, for the heaven cannot contain him; yet so in heaven as there to manifest his glory, for it is his throne (Ps 103:19), and it is to believers a throne of grace: thitherward we must direct our prayers, for Christ the Mediator is now in heaven, Heb 8:1. Heaven is out of sight, and a world of spirits, therefore our converse with God in prayer must be spiritual; it is on high, therefore in prayer we must be raised above the world, and lift up our hearts, Ps 5:1. Heaven is a place of perfect purity, and we must therefore lift up pure hands, must study to sanctify his name, who is the Holy One, and dwells in that holy place, Le 10:3. From heaven God beholds the children of men, Ps 33:13,14. And we must in prayer see his eye upon us: thence he has a full and clear view of all our wants and burdens and desires, and all our infirmities. It is the firmament of his power likewise, as well as of his prospect, Ps 150:1. He is not only, as a Father, able to help us, able to do great things for us, more than we can ask or think; he has wherewith to supply our needs, for every good gift is from above. He is a Father, and therefore we may come to him with boldness, but a Father in heaven, and therefore we must come with reverence, Ec 5:2. Thus all our prayers should correspond with that which is our great aim as Christians, and that is, to be with God in heaven. God and heaven, the end of our whole conversation, must be particularly eyed in every prayer; there is the centre to which we are all tending. By prayer, we send before us thither, where we profess to be going.
Source: Matthew Henry's Commentary on the Whole Bible Volume V (Matthew to John)