What is the ruling on raising the hands when supplicating after the obligatory prayer or other prayers, and while supplicating for the deceased at the time of burial, and upon concluding a gathering, and when supplicating for the host of a meal?

Raising the hands in supplication is one of the reasons for its acceptance. The Prophet, peace and blessings be upon him, made extending the hands a reason for the acceptance of supplication, as in the hadith (definition) narrated by Abu Hurairah, reported by Muslim. Abu Dawud and Al-Tirmidhi narrated that the Prophet, peace and blessings be upon him, said: "Indeed, your Lord is Modest and Generous; He is too shy to turn away empty the hands of His servant when he raises them to Him." It has been authentically reported through multiple chains (Mutawatir) that the Prophet, peace and blessings be upon him, used to raise his hands in dua (supplication). This indicates that the default rule for dua is to raise the hands, unless there is evidence to the contrary.