A.T. Robertson Commentary Hebrews 7:6

"but he whose genealogy is not counted from them hath taken tithes of Abraham, and hath blessed him that hath the promises." — Hebrews 7:6 (ASV)

He whose genealogy is not counted (ο μη γενεαλογουμενος). Articular participle with negative μη (usual with participles) of the old verb γενεαλογεω trace ancestry (cf. verse 3)

Hath taken tithes (δεδεκατωκεν). Perfect active indicative of δεκατοω, standing on record in Genesis.

Hath blessed (ευλογηκεν). Perfect active indicative of ευλογεω, likewise standing on record. Note the frequent perfect tenses in Hebrews.

Him that hath the promises (τον εχοντα τας επαγγελιας). Cf. 6:12,13-15 for allusion to the repeated promises to Abraham (Genesis 12:3,7; 13:14; 15:5; 17:5; 22:16-18).