The farmer who planted good seed did not allow his servants to go and remove the weeds among the good seeds because
he wanted to avoid uprooting any good wheat plants along with the weeds. The farmer understood that the roots of the weeds might be intertwined with the roots of the wheat, making it difficult to distinguish between them. Removing the weeds at that point could cause unintentional damage to the growing wheat.
Additionally, the farmer knew that allowing the weeds to grow along the wheat would eventually reveal their true nature. As the wheat flourished and grew, the weeds would become more apparent and distinguishable. This would make it easier for the servants to separate the wheat from the weeds without any risk of damaging the crops.
By waiting until the harvest, the farmer ensured that the wheat would mature fully, making it easier to separate from the weeds, and maximizing the yield of the good seeds. This patience and careful approach allowed the farmer to minimize potential losses and ensure a successful harvest.