Contradiction with Matthew 6:5
This verse warns against ostentatious displays of worship to be seen by others, which can be seen as contradictory to praising openly in the congregation.
Matthew 6:5: And when thou prayest, thou shalt not be as the hypocrites [are]: for they love to pray standing in the synagogues and in the corners of the streets, that they may be seen of men. Verily I say unto you, They have their reward.
Contradiction with Matthew 6:6
This verse encourages private prayer, which contrasts with the public praise described in Psalms 111:1.
Matthew 6:6: But thou, when thou prayest, enter into thy closet, and when thou hast shut thy door, pray to thy Father which is in secret; and thy Father which seeth in secret shall reward thee openly.