Charles Spurgeon Commentary Hebrews 2:15-16

"and might deliver all them who through fear of death were all their lifetime subject to bondage. For verily not to angels doth he give help, but he giveth help to the seed of Abraham." — Hebrews 2:15-16 (ASV)

And deliver them who through fear of death were all their lifetime subject to bondage. For verily he took not on him the nature of angels; but he took on him the seed of Abraham.

Christ's great mission was not to save angels, but to save men.

Therefore he did not come in the nature of angels, but in the nature of men.