2 Kings 20:4

And it came to pass, afore Isaiah was gone out into the middle court, that the word of the LORD came to him, saying,

Isaiah had told the sick Hezekiah that he would die and was still on his way out through the middle court when the Lord stopped him and sent him back.
The message he was to carry was that God had heard Hezekiah's prayer and seen his tears, and would heal him to go up to the house of the Lord on the third day, add fifteen years to his life, and deliver and defend Jerusalem from Assyria for His own sake and for David's sake.
Though one word could have healed him instantly, God directed that a lump of figs be laid as a plaster on the boil, and Hezekiah recovered.
Using such simple appointed remedies in cooperation with nature's laws and divine power does not deny faith but works in harmony with it.

Answer in the Court

Hezekiah lay sick unto death and had received through Isaiah the message that he would die, but he cried out to the Lord for life. His prayer was heard at once, and before Isaiah had gone out into the middle court, while the prophet was still on his way out and still leaving the court, the word of the Lord came to him. God in that moment sent Isaiah back to Hezekiah with the answer.

The answer sent back declared that God had heard the prayer and had seen the tears. He would heal Hezekiah so that on the third day he could go up to the house of the Lord. Fifteen years would be added to his life. Jerusalem would be delivered and defended from Assyria, for His own sake and for David's sake.

Healing Through Appointed Means

God directed that a lump and poultice and bunch of figs be taken and laid as a plaster upon the boil and sore and affected part, and Hezekiah recovered. One word from God would have healed Hezekiah instantly, yet God gave this special direction as part of His providence. Using beneficial remedies in cooperation with natural laws and divine power does not deny faith but works in harmony with faith. This is God's sanction for using remedial agencies together with prayer for the sick, so that people are to cooperate with divine power and use beneficial means.

The simple means supported nature's work of restoration. God thereby turned the caregivers away from treatments that could not restore him and from treatments that hindered restoration, toward a remedy through which his recovery could proceed.

Providence and Later Consequences

The moment belongs to Hezekiah's experience in which the Lord's hand was visible. Affliction may come under God's providence. Dark events whose purpose is not understood can be ordered by God for good. In that ordering God raised Hezekiah from sickness and granted him a new lease of life by adding fifteen years. The turning back of the shadow on the sundial was given as the sign attesting that gift.

That wonder later drew Babylonian ambassadors to inquire concerning the God who had performed it. Hezekiah's subsequent display of the Lord's riches to those visitors became a test. That test revealed what was in his heart.