Hebrews 2:2

2:2 For if the message spoken through angels ¹  proved to be so firm that every violation ²  or disobedience received its just penalty,

Hebrews 4:6

4:6 Therefore it remains for some to enter it, yet those to whom it was previously proclaimed did not enter because of disobedience.

Hebrews 7:19

7:19 for the law made nothing perfect. On the other hand a better hope is introduced, through which we draw near to God.

Hebrews 12:28

12:28 So since we are receiving an unshakable kingdom, let us give thanks, and through this let us offer worship pleasing to God in devotion and awe.

¹ sn The message spoken through angels refers to the OT law, which according to Jewish tradition was mediated to Moses through angels (cf. Deut 33:2; Ps 68:17-18; Acts 7:38, 53; Gal 3:19; and Jub. 1:27, 29; Josephus, Ant. 15.5.3 [15.136]).

² tn Grk “through angels became valid and every violation.”