Dry Ablution and Combining Prayers for the Sick
Question: May a sick person combine the Zuhr and ʿAsr prayers, and the Maghrib and ʿIshāʾ prayers, and perform a separate dry ablution for each obligatory prayer?
Answer: With regard to dry ablution—yes. A patient may perform dry ablution when illness prevents him from carrying out minor ablution, for Allah, exalted is He, has granted the one who cannot wash himself the concession of dry ablution for each prayer. Moreover, if he performs dry ablution and his state of purity is not nullified, he may offer several prayers with that same dry ablution, because, according to the sound view, dry ablution carries the same ruling as minor ablution as long as nothing that breaks ablution has occurred.
If, however, he is able to perform minor ablution, then he must do so even while ill, even if someone has to assist him.
Question: And what about combining the prayers?
Answer: A sick person may combine Zuhr with ʿAsr and Maghrib with ʿIshāʾ, praying them in the time of either one—whether as an advance combination or a delayed combination—whichever is easier for him, provided that he genuinely needs to combine. If he does not need to combine, he must pray each prayer at its appointed time.

Dry Ablution without a Legitimate Excuse
Question: Some people perform all their prayers with dry ablution. I have advised them many times, but they have not heeded my advice. Is a prayer offered in this way valid? Please clarify, and may Allah bless you.