Hebrews 10:23

10:23 And let us hold unwaveringly to the hope that we confess, for the one who made the promise is trustworthy.

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 11:11

11:11 By faith, even though Sarah herself was barren and he was too old, ¹  he received the ability to procreate, ²  because he regarded the one who had given the promise to be trustworthy.

Hebrews 12:26

12:26 Then his voice shook the earth, but now he has promised, “I will once more shake not only the earth but heaven too.” ³ 

¹ tn Grk “past the time of maturity.”

² tn Grk “power to deposit seed.” Though it is not as likely, some construe this phrase to mean “power to conceive seed,” making the whole verse about Sarah: “by faith, even though Sarah herself was barren and too old, she received ability to conceive, because she regarded the one who had given the promise to be trustworthy.”

¹ sn A quotation from Hag 2:6.