tc Most mss (B* C E Ψ 𝔐 sy bo) read θεοῦ (theou, “of God”) here instead of κυρίου (kuriou, “of the Lord”). Other mss, among them some important early witnesses (𝔓74 א A B2 33 81 323 945 1175 1739 al sa), read κυρίου. The external evidence favors κυρίου, though not decisively. Internally, the mention of “God” in v. 43, and especially “the word of God” in v. 46, would provide some temptation for scribes to assimilate the wording in v. 44 to these texts.

sn The word of the Lord is a technical expression in OT literature, often referring to a divine prophetic utterance (e.g., Gen 15:1, Isa 1:10, Jonah 1:1). In the NT it occurs 15 times: 3 times as ῥῆμα τοῦ κυρίου (rhēma tou kuriou; Luke 22:61, Acts 11:16, 1 Pet 1:25) and 12 times as λόγος τοῦ κυρίου (logos tou kuriou; here and in vv. 48 and 49; Acts 8:25; 15:35, 36; 16:32; 19:10, 20; 1 Thess 1:8, 4:15; 2 Thess 3:1). As in the OT, this phrase focuses on the prophetic nature and divine origin of what has been said.