With one accord (ομοθυμαδον). A concert of voices as already seen by the word in Acts 1:14; Acts 2:46 and later in Acts 5:12; Acts 7:57; Acts 15:25.

O Lord (Δεσποτα). Our word despot. Old word for relation of master to slaves or household servants (1. Timothy 6:1; 2. Timothy 2:21; Titus 2:9; 1. Peter 2:18). Simeon thus addressed God (Luke 2:29). So in 2. Peter 2:1; Judges 1:4; Revelation 6:10. See "slaves" in verse Acts 4:29.