New Defender's Study Bible Notes
3:10 neither should he eat. From the very beginning, God has ordained that men should work for their food (Genesis 2:15-16). This became even more necessary with the entrance of sin and the curse (Genesis 3:17-19). We shall even continue to work, serving the Lord, in the new earth (Revelation 22:3). It is altogether inexcusable for Christians, when they are no longer children, to expect others to provide their sustenance while they stand idle, even if they offer some spiritual excuse for not working.
3:12 quietness. “Study to be quiet, and to do your own business, and to work with your own hands,” Paul had already admonished them in his first epistle (I Thessalonians 4:11). Note also Ephesians 4:28.