Is it permissible for a sick person to pray while sitting on a chair?
All perfect praise be to Allah, The Lord of the Worlds It is permissible for a sick person, who is unable to stand up, to offer prayer while sitting on a chair. If he/she was unable to prostrate while on the chair, the he/she should pray while sitting on the ground, but if he/she was neither able to bow (Roku),nor to prostrate, then he can do them while sitting on the chair. And Allah Knows Best.
What is the recommended supplication (Du'a) upon breaking the fast, and is it recited before or after breaking it?
All praise is due to Allah, and peace and blessings be upon our master, the Messenger of Allah.
It is recommended (Mustahabb) for a fasting person to recite upon breaking the fast—that is, immediately after eating or drinking—the supplication: "Allahumma laka sumtu wa 'ala rizqika aftartu" (O Allah, for You I have fasted, and with Your provision I have broken my fast).
This is because our master, the Prophet (peace and blessings be upon him), used to say this. The narration was recorded by Abu Dawud with a good (Hasan) chain of transmission, albeit in a Mursal form (a narration where a Successor reports directly from the Prophet). Shaykh al-Islam Imam Ibn Hajar al-Haytami (may Allah have mercy upon him) stated: "Its Mursal status is inconsequential, as it pertains to virtuous deeds (Fada'il); furthermore, it was connected (Mawsul) through another chain of transmission." [Tuhfat al-Muhtaj, Vol.3/P.425]
It is also recommended to recite: "Dhahaba al-dhama'u wa ibtallat al-'uruqu wa thabata al-ajru in sha' Allah" (The thirst has gone, the veins are moistened, and the reward is confirmed, if Allah wills).
This was recorded by Abu Dawud with a good (Hasan) chain. Our leading jurists (Imams) have explicitly stated that it is recommended for the fasting person to combine both supplications.
Imam al-Bajuri (may Allah have mercy upon him) stated:
"And his saying following his breaking of the fast—that is, it is recommended to say: 'O Allah, for You I have fasted, upon Your provision I have broken my fast, in You I have believed, to You I have submitted, and upon You I have relied. The thirst has gone, the veins are moistened, and the reward is confirmed, if Allah wills. O You of vast bounty, forgive me. Praise be to Allah Who aided me so that I fasted, and provided for me so that I broke my fast. O Allah, grant us success in fasting, enable us to stand in night prayer during it, and aid us in it while people sleep, and admit us to Paradise in peace.'" [Hashiyat al-Bajuri, Vol.1/P.562]
Furthermore, the fasting person may supplicate with whatever good he or she wishes, for the supplication of a fasting person is answered. Al-Bayhaqi recorded on the authority of Anas ibn Malik that the Messenger of Allah (peace and blessings be upon him) said: "Three supplications are not rejected: the supplication of a parent for his child, the supplication of a fasting person, and the supplication of a traveler." And Allah Almighty knows best.
What are the categories of the livestock permissible for Udhiyah?
In the Name of Allah, and may peace and blessings be upon our Master, the Messenger of Allah.
An Udhiyah (sacrificial offering) is only valid if it is selected from Al-An'am (livestock), which includes: camels, cattle, and sheep or goats—whether male or female, and even if castrated. Allah Almighty says {what means}: "And for all religion We have appointed a rite [of sacrifice] that they may mention the name of Allah over what He has provided for them of [sacrificial] livestock." (Al-Hajj/ 34)
In terms of preference, camels are considered the best choice, followed by cattle, then sheep, and finally goats.
A single sheep or goat is valid as a sacrifice on behalf of one person. However, a single camel or cow can be shared by up to seven people. This is based on the narration of Jabir (may Allah be pleased with him), who said: "In the year of Al-Hudaybiyah, we sacrificed along with the Messenger of Allah (peace and blessings be upon him) a camel on behalf of seven people, and a cow on behalf of seven people." (Narrated by Muslim)
(Note: The term "Badanah" used in the original Arabic text specifically refers to a camel in this context). And Allah the Almighty Knows Best.
Who is the one deemed "able" (al-qādir), for whom the uḍḥiyah (sacrificial offering) is sunnah?
All praise is due to Allah, and peace and blessings be upon our master, the Messenger of Allah ﷺ.
The one who is deemed "able" (al-qādir) [to perform the uḍḥiyah, i.e., the sacrifice] is someone who possesses wealth sufficient to acquire the sacrificial animal, over and above what is needed to cover his own living expenses and the living expenses of his wife and children — or of anyone else whose financial support (nafaqah) is legally obligatory upon him — for the day of ‘Eid and the three days of Tashrīq [that follow it], since this is the designated time period for the sacrifice. And Allah, the Exalted, knows best.