In the essay by Thomas Brooks, Volume 1 Works, Brooks expounds about this sin in "The Mute Christian Under the Smarting Rod". As part of the valuable treatise on Psalm 39:9 he expounds the sin of murmering and complaining. Paul wrote to the Philippians: Do all things without grumbling [complaining] or disputing [quarrelling] (2:14). I have added the square brackets.
Which is easiest? To give thanks or to complain and grumble. The latter comes natural to us as sinners. What is more, we have many records in the Old Testament where the people of God grumbled against the Lord and Moses and the Lord judged his people. Note that grumbling is often directed to the Lord's elders. Religious professors get dissatisfied and they feel they have to target their grumbling somewhere and it often at God and his leaders. Such persons rarely think to examine their own sinful heart and work to take the beam out of their own eye (Matthew chapter 7). Which best describes you? Are you willing to humble yourself before the Lord concerning this sin of murmuring?
The Lord does not care much for false religious profession, hypocrisy or sedition. May we walk by God's grace in peace, love and truth.
Psalm 39:9 reads: "I am mute; I do not open my mouth, for it is you who have done it".
Thomas Brooks writes against this sin with 12 headings (Works, Volume 1, pages 334-341):
1. First consider that murmuring speaks out many a root of bitterness to be strong in your soul.
2. Second, consider that the Holy Spirit has a set a brand of infamy among murmurers. He has stigmatised them for ungodly persons.
3. Third, consider that murmuring is the mother-sin; it is the mother of harlots, the mother of all abominations; a sin that breeds other sins.
4. Fourth, consider that murmuring is a God-provoking sin; it is a sin that provokes God not only to afflict, but also to destroy a people.
5. Fifth, consider, that murmuring is the devil's image, sin, and punishment.
6. Sixth, consider, that murmuring is a mercy-embittering sin, a mercy-souring sin.
7. Seventh, consider that murmuring is a mercy-destroying sin, a mercy-murdering sin.
8. Eighth, consider that murmuring unfits the soul for duty.
9. Ninth, consider that murmuring unmans a man; it strips him of all reason and understanding.
10. Tenth, murmuring is a time-destroying sin.
11. Eleventh, consider this Christians, that of all men in the world, you have least cause, yea, no cause, to be murmuring and muttering under any dispensation that you meet with in this world.
12. Twelfth, and last, consider that murmuring makes the life of man invisibly miserable.
If you are convicted of this sin, then why not come to Christ Jesus the mediator and ask for forgiveness but also for mercy. Forsake this wretched sin and drink from the living waters offered in the gospel.
John 7:37-39 "On the last day of the feast, the great day, Jesus stood up and cried out, “If anyone thirsts, let him come to me and drink. Whoever believes in me, as the Scripture has said, ‘Out of his heart will flow rivers of living water.’ ” Now this he said about the Spirit, whom those who believed in him were to receive, for as yet the Spirit had not been given, because Jesus was not yet glorified".