Hebrews 7:5

7:5 And those of the sons of Levi who receive the priestly office have authorization according to the law to collect a tithe from the people, that is, from their fellow countrymen, although they too are descendants of Abraham.

Hebrews 12:17

12:17 For you know that later when he wanted to inherit the blessing, he was rejected, for he found no opportunity for repentance, although he sought the blessing with tears.