Charles H. Spurgeon on Psalms 57:4

My soul is among lions. He was a very Daniel. Howled at, hunted, wounded, but not slain. His place was in itself one of extreme peril, and yet faith made him feel himself secure, so that he could lie down. The cave may have reminded him of a lion's den, and Saul and his band shouting and yelling in their disappointment at missing him, were the lions; yet beneath the divine shelter he finds himself safe. And I lie even among them that are set on fire. Perhaps Saul and his band kindled a fire in the cavern while they halted in it, and David was thus reminded of the fiercer fire of their hate which burned within their hearts. Like the bush in Horeb, the believer is often in the midst of flames, but never consumed. It is a mighty triumph of faith when we can lie down even among firebrands and find rest, because God is our defence. Even the sons of men, whose teeth are spears and arrows, and their tongue a sharp sword. Malicious men carry a whole armoury in their mouths; they have not harmless mouths, whose teeth grind their own food as in a mill, but their jaws are as mischievous as if every tooth were a javelin or an arrow. They have no molars, all their teeth are canines, and their nature is canine, leonine, wolfish, devilish. As for that busy member the tongue, in the case of the malicious, it is a two edged, keen, cutting, killing sword. The tongue, which is here compared to a sword, has the adjective sharp added to it, which is not used in reference to the teeth, which are compared to spears, as if to show that if men were actually to tear us with their teeth, like wild beasts, they could not thereby wound us so severely as they can do with their tongues. No weapon is so terrible as a tongue sharpened on the devil's grindstone; yet even this we need not fear, for "No weapon that is formed against thee shall prosper, and every tongue that riseth against thee in judgment thou shalt condemn."