Is it permissible to offer an Udhiyah on behalf of another without their permission?
Praise be to Allah, and peace and blessings be upon our master, the Messenger of Allah.
It is not permissible for a person to offer a sacrifice (Udhiyah) on behalf of someone else without their permission, except in the following cases: if he sacrifices on behalf of the members of his household, if a guardian sacrifices from his own wealth on behalf of his ward, or if the Imam (ruler) sacrifices from the public treasury (Bayt al-Mal) on behalf of the Muslims. And Allah the Almighty knows best.
What is the ruling on swallowing phlegm while fasting?
If a fasting person intentionally swallows phlegm, their fast is invalid, as it is possible to avoid it.
However, if they swallow it unintentionally, their fast remains valid.
Phlegm is impure and should be avoided.
What is the ruling on performing dry ablution (tayammum) on a wall or stone?
One of the conditions for tayammum is that it be with pure, clean dust (soil). It is not valid to perform tayammum by striking stones, a wall, sand that has no dust (i.e., that does not produce dust), pebbles alone, or clay, as these are not from the earth or its same category. And Allah the Almighty knows best.
What is the ruling on congratulating others on the arrival of Ramadan?
Congratulating others on the arrival of Ramadan is permissible.
If someone does it to express their love for worship and the blessings of Ramadan, and congratulates their fellow Muslim, they have done something good.
The Prophet ﷺ said: "Shall I not tell you something that, if you do it, you will love one another? Spread peace (Salam) among yourselves." [Narrated by Muslim]
Giving Salam is a prayer for peace and safety.