What is the ruling on one who feels ashamed to seek forgiveness (istighfar) with the intention of asking for sustenance, children, and marriage, believing that istighfar should only be for regretting sins, and that whoever seeks forgiveness to ask for these blessings is not sincere in their repentance?

The most complete form is for istighfar (seeking forgiveness) and repentance to be purely for the sake of Allah the Almighty, without desiring any worldly عوض (recompense). However, there is no harm in seeking forgiveness with the intention of attaining good and warding off evil. It is permissible for a servant to seek forgiveness as an act of drawing closer to Allah and seeking what He has promised in terms of worldly rewards. Yet, the most complete form is to dedicate istighfar and all acts of worship solely to Allah. Sheikh Ibn Uthaymeen mentioned that there is no fault in someone who desires both the good of this world and the Hereafter through their actions, citing the Almighty's words: {And whoever fears Allah – He will make for him a way out and will provide for him from where he does not expect.} The fundamental principle is that we should not assign a worldly share to acts of worship.