Contradiction with Matthew 6:7
While Psalms 119:54 speaks of statutes as songs, Matthew 6:7 warns against vain repetitions, suggesting that simply reciting words isn't inherently meaningful.
Matthew 6:7: But when ye pray, use not vain repetitions, as the heathen [do]: for they think that they shall be heard for their much speaking.
Contradiction with Ecclesiastes 3:1
Psalms 119:54 presents a view of ongoing joy in God's laws, whereas Ecclesiastes 3:1 suggests there is a time for different emotions, not constant singing.
Ecclesiastes 3:1: To every [thing there is] a season, and a time to every purpose under the heaven:
Contradiction with Isaiah 29:13
Psalms 119:54 finds joy in God's statutes, but Isaiah 29:13 points out that adherence can become mere lip service without sincere devotion.
Isaiah 29:13: Wherefore the Lord said, Forasmuch as this people draw near [me] with their mouth, and with their lips do honour me, but have removed their heart far from me, and their fear toward me is taught by the precept of men:
Contradiction with Amos 5:23
Psalms 119:54 sees God's laws as songs, but Amos 5:23 warns against insincere worship, implying that songs alone can be displeasing to God.
Amos 5:23: Take thou away from me the noise of thy songs; for I will not hear the melody of thy viols.
Contradiction with Matthew 15:8-9
In contrast to the joyful embrace of law in Psalms 119:54, Matthew 15:8-9 criticizes those whose worship is superficial and not rooted in genuine heart devotion.
Matthew 15:8-9: This people draweth nigh unto me with their mouth, and honoureth me with [their] lips; but their heart is far from me.