The rest of which the text speaks is the rest of a being who has found again his proper and congenial sphere. In reconciliation to God through Jesus Christ the soul regains its lost equilibrium, finds again the centre of repose for which it had been sighing in vain. "Come unto Me, all ye that labour and are heavy-laden," is the invitation of incarnate love; "and I will give you rest." And in the soul that yields to this invitation there rises the response of its deepest nature, the instinctive throb of a new yet natural affection, the calm sense of existence fulfilled and unexplained hope and desire solved in fruition the witness in its own inmost consciousness that its true rest is found at last.
I. The rest of which the text speaks is not bodily or physical, but mental or spiritual, rest. (1) Bodily repose reaches not to the true centre of man's peace; but mental repose entrenches itself in the deepest region of man's nature, and renders him impregnable to outward assault. (2) Physical repose can only be periodic; the rest of the soul is essentially continuous.
II. The rest of which the psalmist speaks may be described, again, as the rest not of immobility, but of equipoise. In the repose of a saintly spirit there is latent power. The inward repose which, sooner or later, true religion brings, is the result of the final conquest and subjugation of man's lower nature. The peace of the holy mind is the peace not of stagnation, but of self-conquest.
III. The true rest of the soul is that not of inactivity, but of congenial exertion. Labour is rest to the active and energetic spirit. The mind itself does not waste or grow weary; and but for the weight of the weapons wherewith it works, it might think, and imagine, and love on for ever. The service of God, beyond all other kinds of labour, may become the most perfect rest to the soul. As love to Christ deepens in the soul that is truly given to Him, the work which it prompts us to do for Him loses the feeling of effort and passes into pleasure.
IV. This rest is not absolute, but relative. Whilst it is a great thing to be an earnest worker in Christ's service, yet the Christian life is not mainly a life of action, but of trust, not of independent exertion, but of self-abandonment to the working of a mightier agency than ours. Calmly as the midnight voyager sleeps whilst, under watchful guidance, the vessel bears him onwards, so calmly, with such trustful humility, does the believer commit himself and his fates for time and eternity to the unslumbering providence of God.
V. This rest is attainable through Christ alone. "No man cometh unto the Father but by Him." He offers pardon to the guilty, purity to the defiled, peace, joy, hope, heaven, to the wretched, or that which includes them all: that strange, unearthly blessing restto the weary and heavy-laden soul.
J Caird, Sermons,p. 192.
References: Psalms 116:7. M. R. Vincent, Gates into the Psalm Country,p. 215; H. W. Beecher, Christian World Pulpit,vol. xxiii., p. 339. Psalms 116:8. G. Brooks, Outlines of Sermons,p. 105.Psalms 116:9. M. Dix, Sermons Doctrinal and Practical,p. 319.