Hebrews 6:13

6:13 Now when God made his promise to Abraham, since he could swear by no one greater, he swore by himself,

Hebrews 10:12

10:12 But when this priest ¹  had offered one sacrifice for sins for all time, he sat down at the right hand ²  of God,

[10:12]  ¹ tn Grk “this one.” This pronoun refers to Jesus, but “this priest” was used in the translation to make the contrast between the Jewish priests in v. 11 and Jesus as a priest clearer in English.

[10:12]  ² sn An allusion to Ps 110:1.