John Calvin Commentary Exodus 15:26

"and he said, If thou wilt diligently hearken to the voice of Jehovah thy God, and wilt do that which is right in his eyes, and wilt give ear to his commandments, and keep all his statutes, I will put none of the diseases upon thee, which I have put upon the Egyptians: for I am Jehovah that healeth thee." — Exodus 15:26 (ASV)

If you will diligently hearken. Moses now unfolds what was the statute or ordinance which God promulgated. For here the reference is not to the whole law which was afterwards given on Mount Sinai, but to the special admonition which served to chastise the wickedness of the people.

The sum of it is, that if the Israelites were tractable and obedient to God, He on the other hand would be kind and bountiful to them. And it is an implied rebuke, so that they might know that whatever troubles they experienced were brought upon them by their sins.

He proposes the Egyptians to them as an example, whose rebellion they had seen punished by God with such severe and heavy calamities. I am the Lord that heals you, is immediately added in confirmation, as if he had said that the Israelites were liable to the same plagues which had been inflicted on the Egyptians, and were only exempt from them because God acted as a healer.

And truly, whatever diseases afflict the human race, we may see in them, as in so many mirrors, our own miseries, so that we may perceive that there is no health in us, except insofar as God spares us.

We are also taught in this verse that this is the rule of a good life: when we obey God’s voice and study to please Him. But because the will of God was to be proclaimed soon after in the law, He expressly commands them to give ear to His commandments, and to keep His statutes.¹⁷⁰

I do not know whether there is any force in the opinion of some who distinguish the word חקים, chokim, (which is usually translated as “statutes,”) from precepts, as if they were mere declarations of His pleasure to which no reason is attached. Let it suffice that God’s law is commended under many names, to remove any pretext for ignorance.

¹⁷⁰ “Je ne m’arreste point aux mots Hebrieux, pource que je ne voy pas qu’il en soit besoin pour les gens de nostre langue;” I do not stay to speak of the Hebrew words, because I do not see that it is necessary for those of our language. — Fr..