Thomas Boston (d. 1732), along with many other volumes, wrote a commentary on the Westminster Shorter Catechism. I’ve enjoyed using it in my studies and sermons on the Ten Commandments. Below I’ve written a section where Boston talks about one of the implications of the 9th commandment: rather than lying, we should speak well of our neighbor and promote his good name (WSC Q/A 77; cf HC Q/A 112). The question is, what does the 9th commandment require of us towards our neighbors?
1. A charitable opinion and esteem of our neighbors (1 Cor. 13:7); being ready to hope the best of them, unless the contrary be evident.
2. A desire of, and rejoicing in, their good name and reputation (Rom. 1:8). We are to love them as ourselves, and therefore should be glad of the sweet savor of their name, though their reputation outshine ours.
3. Sorrowing and grieving for their faults (2 Cor. 12:21). The blasting of anybody’s name by their sins, should make us mourn, and the rather that the same root of bitterness is in all naturally: and they are the deeper in God’s debt that get through the world with an unblemished reputation.
4. Covering their infirmities with the mantle of love (1 Pet. 4:8). Everybody has some weak side, and needs a cover from others in love: and it is a dangerous business to aggravate and blaze abroad this to their dishonor.
5. Freely acknowledging the gifts and graces that are in any (1 Cor. 1:4–7). As none are so good but they have some discernible infirmity, so hardly is one so bad but there is some one thing or another praise-worthy in them. And if it were but one thing, it is our duty frankly to own it.
6. Defending their innocence, as Ahimelech did David’s (1 Sam. 22:14): “And who among all your servants is as faithful as David, even the king’s son-in-law, who is captain over your guard, and is honored in your house?” (NASB). It is necessary and just to defend the innocent, especially if absent, against the poisonous bites of a viperous tongue lest we be held consenting to the tongue-murder of him, in God’s account.
7. An unwillingness to receive an ill report of them, and a readiness to admit a good report of them (1 Cor. 13:6, 7. Ps. 15:3). Love readily opens the door to a good report of our neighbor, but is not very hasty to let in an evil one, being truly sorry if it should be true.
8. Discouraging tale bearers, flatterers, and slanderers, who go about gathering all the filth they can find to throw upon the name and reputation of others. These should be discouraged as the pests of human society, as David did, ‘Whoever secretly slanders his neighbor, him I will destroy’ (Ps. 101:5 NASB).
9. Lastly, watching over one another, giving sound and seasonable admonitions, checks, and reproofs, for what is ill or ill like in others (Lev. 19:17); and telling themselves of it, so as it may not be blabbed out without necessity: whereby both their souls might be timely preserved from the snare, and their good name preserved too.
The above quotes are found in Thomas Boston, The Whole Works of Thomas Boston: An Illustration of the Doctrines of the Christian Religion, Part 2, ed. Samuel M‘Millan, vol. 2 (Aberdeen: George and Robert King, 1848), 316–317.