Saying: "O Allah! Forgive me if You Will." (Kitaabul Tawheed)
Explaination of Muhammad Ibn Abdul-Wahaab (rahimallah): Kitaabul-Tawheed
By Shaykh Abdur-Rahman Al-Saa'dee (rahimallah)
Saying: "O Allah! Forgive me if You Will." pgs.235-236
In the Sahih from Abu Hurayrah that Allah's Messenger (alayhee salatul wasalaam) said, "None of you may say, 'O Allah forgive me if you will.' O Allah have mercy o要 me if you will.' But be resolved o要 the issue, for there is no difficulty for Allah." [Al-Bukhari and Muslim]
And with Muslim, "But let your hope be great, for nothing is too great for Allah to give it."
Important Points (Ibn Abdul Wahaab)
Commentary by Shaykh Al-Saa'dee
Saying: "O Allah! Forgive me if You Will."
Every occurence is by Allah's will and intent. So when seeking a religious matter, like asking for mercy or forgiveness, or when seeking something related to this life, like good health, provisions, and the like, then the worshipper is ordered to ask for it from his Lord in a manner imploring Him of its urgency, and being certain about it. This kind of seeking is the core and marrow of uboodiyah.
This is will not be complete unless the request is a certain o要e, without conditioning it by "if you will", and the matter must be something that is good, having no harm in it. Allah is not o要e whom something is too grand for.
Here there is a clear distinction between this general request, and cases of asking for something specific. Like asking for things that may not bring any benefit or good, or it's result is not a positive good for the worshipper. So the worshipper asks his Lord, and he relies upon his Lord to chose the best manner for him, like in the case of du'a ; "O Allah cause me to live while living is good for me, and take me when You know that death is better for me." Or like the du'a of istikharah.
So understand the difference, the subtle importance of the distinction between seeking good things that are well known for their benefit, being free of any harm, and the supplicant is resolved when seeking it, not being uncertain about it-and seeking a matter which the worshipper is not sure if there may be a punishment for it, nor can he be sure of the benefit over the harm of it. So the supplicant leaves the choice to his Lord, the o要e who encompasses everything in His knowledge, control, mercy, and beneficence