What is the wisdom behind stipulating the waiting period (iddah) for a widow as four months and ten days?

Knowing the wisdom behind Allah's command is either by explicit mention in the Qur’an and Sunnah, or by the inference of scholars, who may err. What is required is submission to Allah's command, believing that He is All-Wise. The waiting period ('iddah) for widowhood is four months and ten days, and the inferred wisdom is to ensure that the womb is clear of pregnancy. It has been mentioned that the fetus moves after the soul is breathed into it, and the duration of the 'iddah is a precaution for this. It is not permissible to violate a Sharia ruling based on an inferred wisdom, because it might be incorrect.