Contradiction with Exodus 20:4
Exodus 20:4 forbids the making of any graven image or likeness, while Exodus 25:20 describes the construction of cherubim for the Ark.
Exodus 20:4: Thou shalt not make unto thee any graven image, or any likeness [of any thing] that [is] in heaven above, or that [is] in the earth beneath, or that [is] in the water under the earth:
Contradiction with Isaiah 44:9-10
Isaiah 44:9-10 condemns idol makers and worshipers, whereas Exodus 25:20 describes the making of cherubim, which are crafted figures.
Isaiah 44:9-10: They that make a graven image [are] all of them vanity; and their delectable things shall not profit; and they [are] their own witnesses; they see not, nor know; that they may be ashamed. [delectable: Heb. desirable]
Contradiction with Deuteronomy 4:15-18
Deuteronomy 4:15-18 warns against making images of any creature, while Exodus 25:20 commands the creation of cherubim, which are representations of heavenly beings.
Deuteronomy 4:15-18: Take ye therefore good heed unto yourselves; for ye saw no manner of similitude on the day [that] the LORD spake unto you in Horeb out of the midst of the fire: