Speak ye comfortably - Hebrew, על־לב ‛al-lēb as in the margin, 'To the heart.' The heart is the seat of the affections. It is there that sorrow and joy are felt. We are oppressed there with grief, and we speak familiarly of being pained at the heart and of being of a glad or merry heart. To speak 'to the heart,' is to speak in such a way as to remove the troubles of the heart; to furnish consolation, and joy. It means that they were not merely to urge such topics as should convince the understanding, but such also as should be adopted to minister consolation to the heart. So the word is used in Genesis 34:3 : 'And his soul clave unto Dinah - and he loved the damsel, and spake kindly (Hebrew, to the heart) of the damsel;' Genesis 50:21 : 'And he comforted them, and spoke kindly unto them' (Hebrew, to their hearts); see also 2 Chronicles 32:6.

To Jerusalem - The direction is not merely to speak to the people in Babylon, but also to comfort Jerusalem itself lying in ruins. The general direction is, therefore, that the entire series of topics of consolation should be adduced - the people were to return from their bondage, and Jerusalem was to be rebuilt, and the worship of God to be restored.

And cry unto her - In the manner of a crier; or one making public and loud proclamation (compare Isaiah 40:3, Isaiah 40:9). Jerusalem is here personified. She is addressed as in ruins, and as about to be rebuilt, and as capable of consolation from this promise.

That her warfare is accomplished - Septuagint, 'That her humiliation (ταπείνωσις tapeinōsis) is accomplished.' The Hebrew word (צבא tsâbâ', 'warfare') properly means an army or host (compare the note at Isaiah 1:9), and is usually applied to an army going forth to war, or marshalled for battle 2 Samuel 8:16; 2 Samuel 10:7. It is then used to denote an appointed time of service; the discharge of a duty similar to an enlistment, and is applied to the services of the Levites in the tabernacle Numbers 4:28 : 'All that enter in to perform the service (Hebrew, to war the warfare), to do the work in the tabernacle of the congregation.' Compare Numbers 8:24-25. Hence, it is applied to human life contemplated as a warfare, or enlistment, involving hard service and calamity; an enlistment from which there is to be a discharge by death.

Is there not a set time (Hebrew, a warfare) to man upon earth?

Are not his days as the days of an hireling?

Isaiah 40:2 Parallel Commentaries

The Secret of Immortal Youth
'Even the youths shall faint and be weary, and the young men shall utterly fall. But they that wait upon the Lord shall renew their strength; they shall mount up with wings as eagles; they shall run and not be weary; and they shall walk and not faint.'--ISAIAH xl. 30, 31. I remember a sunset at sea, where the bosom of each wavelet that fronted the west was aglow with fiery gold, and the back of each turned eastward was cold green; so that, looking on the one hand all was glory, and on the other …
Alexander Maclaren—Expositions of Holy Scripture

Prayer and Devotion
"Once as I rode out into the woods for my health, in 1737, having alighted from my horse in a retired place, as my manner commonly had been to walk for divine contemplation and prayer, I had a view that for me was extraordinary, of the glory of the Son of God. As near as I can judge, this continued about an hour; and kept me the greater part of the time in a flood of tears and weeping aloud.. I felt an ardency of soul to be what I know not otherwise how to express, emptied and annihilated; to love …
Edward M. Bounds—The Essentials of Prayer

The God of all Comfort
"Blessed be God, even the Father of our Lord Jesus Christ, the Father of mercies and the God of all comfort; who comforteth us in all our tribulations, that we may be able to comfort them which are in any trouble, by the comfort wherewith we ourselves are comforted of God." Among all the names that reveal God, this, the "God of all comfort," seems to me one of the loveliest and the most absolutely comforting. The words all comfort admit of no limitation and no deductions; and one would suppose that, …
Hannah Whitall Smith—The God of All Comfort