John Gill's Bible Commentary
Ver. 44. David therefore called him Lord , etc.] Or, my Lord, as the Syriac and Ethiopic versions read; or, his Lord, as the Arabic version. This is the inference from the words before cited ( <19B001> Psalm 110:1), upon which the following question is asked, how is he then his son ? how can these things be reconciled? in what sense can he be both his Lord and son? (see Gill on Matthew 22:45).
Matthew Henry Commentary
Verses 39-47 - The scribes commended the reply Christ made to the Sadducees about the resurrection, but they were silenced by a question concerning the Messiah. Christ, as God, was David's Lord; but Christ, as man, wa David's son. The scribes would receive the severest judgement for defrauding the poor widows, and for their abuse of religion particularly of prayer, which they used as a pretence for carrying of worldly and wicked plans. Dissembled piety is double sin. Then let u beg of God to keep us from pride, ambition, covetousness, and ever evil thing; and to teach us to seek that honour which comes from his alone __________________________________________________________________
Greek Textus Receptus
δαβιδ 1138 N-PRI ουν 3767 CONJ κυριον 2962 N-ASM αυτον 846 P-ASM καλει 2564 5719 V-PAI-3S και 2532 CONJ πως 4459 ADV-I υιος 5207 N-NSM αυτου 846 P-GSM εστιν 2076 5748 V-PXI-3S
Robertson's NT Word Studies
20:44 {David therefore} (daueid oun). Without ei as in #Mt 22:45. On the basis of this definite piece of exegesis (oun, therefore) Jesus presses the problem (pws, how) for an explanation. The deity and the humanity of the Messiah in #Ps 110 are thus set forth, the very problems that disturbed the rabbis qen and that upset many critics today.