I shall consider what is implied in the soul's following hard after God, and then enquire the reason of it.
1. Following hard after God supposes,
(a) A previous acquaintance with him. An unknown good, be it ever so desirable in itself, cannot be the object of desire. Hence, when God shines into the heart, it is to give the light of the knowledge of the glory of God in the face of Jesus Christ, as the foundation of all gracious exercises, and especially as the source of all fervent desires after him.
(b) Following hard after God is expressive of ardent and intense desires. It does not consist in cold and languid wishes, but insatiable longings after communion with God and conformity to his will.
(c) It implies laborious exertion. My soul followeth, it followeth hard after thee. Not earth nor heaven merely is the object of pursuit, but God himself. And the desires of a truly renewed soul are not sluggish and ineffectual; they lead him to the use of all appointed means, and to the exertion of his utmost endeavours till the object be attained.
(d) Perseverance in seeking. To follow implies this, and to follow hard implies it more strongly. It is as if the psalmist had said, "Does God retire? I will pursue. Does he withhold the blessing? I will wrestle with him till I obtain it. He long waited to be gracious, and I will now wait till he is so."
2. We are to enquire the reason why David thus followed hard after God.
(a) Guilt and distress followed hard after him.
(b) His enemies also followed hard after him. Satan did so, and once and again caused him to stumble and fall.
(c) He had followed hard after other things to no purpose.
(d) We may add the powerful attractions of divine grace.