Understanding is a wellspring of life unto him that hath it,.... "The master" or "owner of it" (k). As he only is to whom an understanding is given; for, whatever understanding men may have of natural and civil things, they have none of things spiritual and divine, unless it be given them by Christ. This is no other than the grace of the Spirit of God, who is a spirit of wisdom and revelation in the knowledge of Christ; and this is a well of living water, springing up unto everlasting life, and it issues in it; with the knowledge of Christ, and God in Christ, eternal life is connected, Joh 4:14; and as this knowledge and understanding of things is communicated by wise and knowing men, they are the means and instruments of the spiritual life of those to whom they minister, and are made useful; but the instruction of fools is folly; the best instruction they are capable of giving is downright folly, and issues in death. (k) "domini sui", Pagninus; "domino suo", Mercerus, Gejerus; "dominorum suorum", Michaelis.