The one wording he told them to drop
Two words that put a condition on the asking.
The words
اغْفِرْ لِي إِنْ شِئْتَ، ارْحَمْنِي إِنْ شِئْتَ، ارْزُقْنِي إِنْ شِئْتَ، وَلْيَعْزِمْ مَسْأَلَتَهُ، إِنَّهُ يَفْعَلُ مَا يَشَاءُ، لاَ مُكْرِهَ لَهُ
Wa-l-yaʿzim masʾalatah, innahu yafʿalu mā yashāʾ, lā mukriha lah
The pronunciation above covers the opening of this passage, not all of it
Let him be firm in his asking. He does what He wills, and no one can force Him.
Where this comes from
Do not say forgive me if You will, have mercy on me if You will, provide for me if You will. Ask outright. The reason given is not that the condition is rude. It is that it is pointless, because nothing was ever going to compel Him anyway.
The full narration
Narrated Abu Huraira:The Prophet (ﷺ) said, "None of you should say: 'O Allah! Forgive me if You wish,' or 'Bestow Your Mercy on me if You wish,' or 'Provide me with means of subsistence if You wish,' but he should be firm in his request, for Allah does what He will and nobody can force Him (to do anything)
Source
Ṣaḥīḥ al-Bukhārī · 7477
- Recorded in Ṣaḥīḥ al-Bukhārī, whose narrations are accepted as authentic