The Greek particle “de”

“De,” a Greek particle, meant “really,” “indeed,” “now,” “therefore.”

“This particle identifies a statement as something definitely established (Matt 13:23; 2 Cor. 12:1 Koine)” (Exegetical Dictionary of the New Testament, 1:294).  It also appears “in commands, giving them an urgency (Luke 2:15; Acts 6:3 v.1.; 13:2; 15:36; 1 Cor. 6:20)” (ibid).