Psalms 106:33

Those that will not wait for God's counsel, shall justly be given up to their own hearts' lusts, to walk in their own counsels. An undue desire, even for lawful things, becomes sinful. God showed his displeasure for this. He filled them with uneasiness of mind, terror of conscience, and self-reproach. Many that fare deliciously every day, and whose bodies are healthful, have leanness in their souls: no love to God, no thankfulness, no appetite for the Bread of life, and then the soul must be lean. Those wretchedly forget themselves, that feast their bodies and starve their souls. Even the true believer will see abundant cause to say, It is of the Lord's mercies that I am not consumed. Often have we set up idols in our hearts, cleaved to some forbidden object; so that if a greater than Moses had not stood to turn away the anger of the Lord, we should have been destroyed. If God dealt severely with Moses for unadvised words, what do those deserve who speak many proud and wicked words? It is just in God to remove those relations that are blessings to us, when we are peevish and provoking to them, and grieve their spirits.

Because they provoked his spirit, so that he spake unadvisedly with his lips. Which seems a small sin compared with that of others, but then it was the sin of Moses, the Lord's chosen servant, who had seen and known so much of the Lord, and therefore it could not be passed by. He did not speak blasphemously, or falsely, but only hastily and without care; but this is a serious fault in a lawgiver, and especially in one who speaks for God. This passage is to our mind one of the most terrible in the Bible. Truly we serve a jealous God. Yet he is not a hard master, or austere; we must not think so, but we must then rather be jealous of ourselves, and watch that we live the more carefully, and speak the more advisedly, because we serve such a Lord. We ought also to be very careful how we treat the ministers of the gospel, lest by provoking their spirit we should drive them into any unseemly behaviour which should bring upon them the chastisement of the Lord. Little do a murmuring, quarrelsome people dream of the perils in which they involve their pastors by their untoward behaviour.