John Calvin's Bible Commentary
Jeremiah 39:18
Then he says, that he would be safe, because the Lord would deliver him in that day And, again, he confirms the same thing, For delivering I will deliver thee, and thou shalt not fall by the sword The Prophet again calls the attention of Ebedmelech to God himself; for we know how all things are in a confusion when cities are taken by storm. Except then Ebedmelech had his mind fixed on God, he could never have retained any hope of deliverance. Hence the Prophet assures him again, that God would be his deliverer. And he adds, Thy soul shall be for a prey This mode of expression has been elsewhere explained. The comparison is taken from those who deem that a great gain which is yet but small, if they get it beyond their expectation, as when a man finds a prey which he had by no means hoped for: he becomes suddenly rich, or increased in his goods; and though the gain may not be great, he yet greatly rejoices. So they who escape alive from present death, have no small reason to be joyful, because their life has been preserved. In the meantime God alludes to those who regard it enough to escape from death, though they may be deprived of all other things. As those who, in shipwreck, cast forth their mer-chandize, and their money, and all they have, deem it enough if they can reach the harbor, and they prefer to beg their bread all their life rather than to sink in the midst of the sea, so he who escapes with his life; though poverty is bitter, yet the horror of death is so great, that he deems his life a great, gain, though stripped of all that he had.
The reason follows, because he trusted in God. Another reason might have been assigned, even because he had not been wanting in his kindness to a holy man, but had extended his hand to him in his extreme misery; but as that office of humanity proceeded from faith and piety, God does here express the chief cause. As then the mercy which Ebedmelech exercised towards the Prophet was an evidence of his piety and faith, here is found the fruit in its own tree, or in its root: and certain it is, that Ebedmelech would have never been so humane towards the Prophet, had he not relied on God and his aid; for unbelief is always timid. There is then no doubt but that the vigor which appeared in Ebedmelech, when he regarded his life in bringing aid to the Prophet, made manifest that faith which is now commended: because then thou hast trusted in me, therefore delivering I will deliver thee, says God. There is now then no doubt but that Ebedmelech had some of the elements of faith and piety. If then God has allowed us to make farther progress, we may feel the more assured that he will be our deliverer; for his grace and his power will ever exceed our faith, how much so ever it may be. Now follows —