They have a sense of the evil that is in the least sin. This is the difference between a tender conscience and a hard heart. One is afraid to offend God in the least matter, the other makes nothing of sin, and so runneth into mischief, Prov. xxviii. 14. Well, then, a man that hath a tender heart is loath to fall into the least sin, he is ever drawing to God to be kept from all sin. When we are earnest in this matter, it is a sign we are sensible what an evil sin is. Men that side with their own lusts and interests may wonder at the frequent requests of the Psalmist here for establishment and preservation from sin. But those that have a tender conscience are like the eye, soon offended, and make it their business to keep it from offence; they are thus solicitous and earnest with God to be upheld.
On Psalm 119