Is wishing for death and illness, and the desire to be buried beside one's deceased father, considered an objection to God's decree and a sin requiring expiation, knowing that these thoughts stem from intense grief and are not an objection to God's decree?

Wishing for death is prohibited, as is wishing for affliction, based on the hadith: "None of you should wish for death due to an affliction that has befallen him. If he must wish for something, let him say: 'O Allah, keep me alive as long as life is better for me, and cause me to die if death is better for me.'" And the hadith: "The best of people is he whose life is long and whose deeds are good." And the hadith: "Ask Allah for pardon and well-being, for no one has been given anything better than well-being after certainty (of faith)."

Therefore, you should frequently supplicate for mercy and forgiveness for your father, and give charity, perform Hajj, and Umrah on his behalf if possible, and strive to raise your children according to Islamic teachings.