'Fast' in the Bible

and Christ, as a Son over his house, whose house are we, if the boldness and the rejoicing of the hope unto the end we hold fast.

for partakers we have become of the Christ, if the beginning of the confidence unto the end we may hold fast,

Having, then, a great chief priest passed through the heavens -- Jesus the Son of God -- may we hold fast the profession,

may we hold fast the unwavering profession of the hope, (for faithful is He who did promise),