KJV:
Desiring to be teachers of the law; understanding neither what they say, nor whereof they affirm.
NASB:
wanting to be teachers of the Law, even though they do not understand either what they are saying or the matters about which they make confident assertions.
KJV:
This is a faithful saying, and these things I will that thou affirm constantly, that they which have believed in God might be careful to maintain good works. These things are good and profitable unto men.
NASB:
This is a trustworthy statement; and concerning these things I want you to speak confidently, so that those who have believed God will be careful to engage in good deeds. These things are good and profitable for men.