Contradiction with Proverbs 27:1
Contradicts the plans made for the future in 1 Corinthians 16:5 by stating one should not boast about tomorrow.
Proverbs 27:1: Boast not thyself of to morrow; for thou knowest not what a day may bring forth. [to...: Heb. to morrow day]
Contradiction with James 4:13-14
Contradicts the certainty of Paul's travel plans in 1 Corinthians 16:5 by highlighting the unpredictability of future plans.
James 4:13-14: Go to now, ye that say, To day or to morrow we will go into such a city, and continue there a year, and buy and sell, and get gain: