Exodus 15:25

And he cried unto the Lord — It is the greatest relief of the cares of magistrates and ministers, when those under their charge make them uneasy, that they may have recourse to God by prayer; he is the guide of the church's guides, and to the chief shepherd, the under shepherds must on all occasions apply themselves: And the Lord directed Moses to a tree, which he cast into the waters, and they were made sweet — Some think this wood had a peculiar virtue in it for this purpose, because it is said, God shewed him the tree. God is to be acknowledged, not only in the creating things useful for man, but in discovering their usefulness. But perhaps this was only a sign, and not a means of the cure, no more than the brazen serpent. There he made a statute and an ordinance, and there he proved them — That is, there he put them upon trial, admitted them as probationers for his favour. In short he tells them, Exodus 15:26, what he expected from them, and that was, in one word, obedience. They must diligently hearken to his voice, and give ear to his commandments, and must take care, in every thing, to do that which was right in God's sight, and to keep all his statutes. Then I will put none of these diseases upon thee — That is, I will not bring upon thee any of the plagues of Egypt. This intimates, that if they were disobedient, the plagues which they had seen inflicted on their enemies should be brought on them. But if thou wilt be obedient, thou shalt be safe, the threatening is implied, but the promise is expressed, I am the Lord that healeth thee — And will take care of thee wherever thou goest.