1 Thessalonians 5:17 - Ellicott's Commentary On The Whole Bible

Pray without ceasing. — Theophylact well says, “This shows the way to ‘rejoice always’ — to wit, incessant prayer and eucharist, for he that has accustomed himself to hold converse with God, and to give thanks to Him over everything that happens as happening well, will evidently have unbroken joy.” Though a man cannot be incessantly praying in words, the mind may be held continuously in an attitude of prayer, even in sleep (Song of Solomon 5:2).