Ibn Majah

1؎: The benefit will be that even if he acts contrary to the oath, expiation (kafarah) will not become obligatory, and the person will not be considered a liar, because his oath was contingent upon the will (mashiyyah) of Allah Ta'ala. It becomes clear that Allah Ta'ala did not will it, so he acted contrary to the oath. This is an excellent way to avoid the expiation of an oath. It is mentioned in the Sahihayn that Sulayman bin Dawud (alayhimas-salatu was-salam) said: "Tonight I will go to seventy women," until the end of the hadith. In it, the Prophet (sallallahu alayhi wa sallam) said: "If he had said 'insha Allah,' his statement would not have been incorrect." And the majority (jumhur) hold the view that when one attaches «إن شاء الله» to an oath, it does not become binding, meaning that breaking it does not make expiation obligatory. However, the condition is that «إن شاء الله» must be said together with the oath itself.