John Gill

And cast ye the unprofitable servant,.... All the servants of Christ are unprofitable with respect to God; for no man can be profitable to him, as he that is wise may be profitable to himself, or others; or in a way of merit, since when they have done the most and best, they have done but their duty: but this man was unprofitable with respect to himself, having not improved the gift and talent bestowed on him; and with respect to men, being of no use for the conversion of sinners, or the comfort of saints, or the edifying of the body of Christ; and brought no honour to his master, and was of no service for the spreading of his Gospel, and the enlargement of his kingdom and interest; and therefore, as one good for nothing, the ministering angels are bid to take him, and cast him into outer darkness: there shall be weeping and gnashing of teeth: he shall be turned out of doors into outer darkness, to be a companion of other unhappy creatures; who are also without, bewailing their miserable condition, and reflecting on their past conduct; whilst faithful, diligent, and laborious servants will be within, partaking of a rich entertainment, prepared by their Lord, accompanied with joy unspeakable, and full of glory: See Gill on Mat 8:12.