Contradiction with Matthew 6:3
This verse advises giving alms in secret, which contradicts the assumption in John 13:29 that Jesus instructed Judas openly about giving something to the poor.
Matthew 6:3: But when thou doest alms, let not thy left hand know what thy right hand doeth:
Contradiction with Proverbs 28:27
This verse states that those who give to the poor will not lack, while the assumption in John 13:29 implies a specific instruction to give to the poor, contrasting with the idea of lacking guidance.
Proverbs 28:27: He that giveth unto the poor shall not lack: but he that hideth his eyes shall have many a curse.
Contradiction with Mark 14:7
The verse declares the poor will always be present, which contrasts the unique and specific moment in John 13:29 thought to be given in the context of Judas' actions.
Mark 14:7: For ye have the poor with you always, and whensoever ye will ye may do them good: but me ye have not always.