What is genre of Hebrews?

Except for introduction, it is homiletic: constant comparisons of old Temple vs Christ. He earned title to all grace and forgiveness once for all -- yet God in His love of good order wants a means or title for giving it out, for which Christ provided saying, "Do this in memory of me" -- Under same external sign as on Holy Thursday, obedient will of Christ is presented as title for giving out graces -- to receive, we must be members of His and be like Him (syn Christo theme, as in answer 175).