Is supplicating with "O Allah, forgive my sin, and expand for me in my home, and bless for me in my provision" during ablution a Sunnah? And what is the correct meaning of the hadith, and when should it be recited?

The aforementioned Hadith (definition) has a disputed authenticity, with the preponderant view being its weakness. Scholars have differed regarding whether Abu Mijlaz Lahiq ibn Humaid heard directly from Abu Musa al-Ash'ari, with some affirming it and others negating it. Consequently, scholarly opinions on the Hadith's authenticity have varied: Al-Nawawi and Ibn al-Qayyim authenticated it, while Ibn Hajar and Al-Albani deemed it weak. Even assuming its authenticity, scholars have differed on the timing of this supplication: whether it is to be recited after ablution, after prayer, or if it encompasses both. The preponderant view is that it is recited after or during prayer, and it is not among the invocations for ablution. The meaning of the supplication: "O Allah, forgive my sin" means to conceal and erase it. "And expand for me in my abode" refers to this world, the Hereafter, and the barzakh (definition) (interim period) through contentment, spaciousness, and mercy. "And bless for me in my provision" means to increase it and develop it through contentment and satisfaction.