Contradiction with Matthew 6:1
This verse advises against publically displaying and boasting about one's contributions, while 1 Chronicles 29:6 describes leaders willingly offering in public.
Matthew 6:1: Take heed that ye do not your alms before men, to be seen of them: otherwise ye have no reward of your Father which is in heaven. [alms: or, righteousness] [of your: or, with your]
Contradiction with Matthew 23:12
This verse states that those who exalt themselves will be humbled, which contrasts with the leaders' public offerings in 1 Chronicles 29:6 where they are honored for their giving.
Matthew 23:12: And whosoever shall exalt himself shall be abased; and he that shall humble himself shall be exalted.
Contradiction with Proverbs 27:2
Advises letting others praise one rather than self-praise, which contrasts with leaders publicly giving offerings in 1 Chronicles 29:6.
Proverbs 27:2: Let another man praise thee, and not thine own mouth; a stranger, and not thine own lips.