For he testifieth
 That is, either David, the penman of the psalm, or rather the Holy Ghost, the enditer of it, or God in the Scripture, in ( Psalms 110:4 ) of this form of citing Scripture, (See Gill on Hebrews 2:6). 
 thou art a priest for ever after the order of Melchisedec;
 see ( Hebrews 5:6 Hebrews 5:10 ) ( 6:20 ) .