Contradiction with Matthew 6:34
While Proverbs 4:26 advises careful planning, Matthew 6:34 suggests not worrying about the future.
Matthew 6:34: Take therefore no thought for the morrow: for the morrow shall take thought for the things of itself. Sufficient unto the day [is] the evil thereof.
Contradiction with James 4:13-14
Proverbs 4:26 emphasizes thought-out planning, but James 4:13-14 warns against presumption in planning.
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:
Contradiction with Luke 12:19-20
Proverbs 4:26 advises establishing a stable path, yet Luke 12:19-20 highlights the futility of planning without regard to unforeseen circumstances.
Luke 12:19-20: And I will say to my soul, Soul, thou hast much goods laid up for many years; take thine ease, eat, drink, [and] be merry.