How does a praying person prostrate?
All perfect praise be to Allah,The Lord of The Worlds It is from Sunnah that he/she sits with both knees on the ground in order to prostrate, then hands, nose and forehead are placed on the same place. In addition, the toes have to touch the ground, and be directed towards the Qiblah (direction of Ka`bah) during prostration. And Allah Knows Best.
What do you say about someone who stays up all night on Laylat al-Qadr but misses Fajr prayer?
Such a person has deprived themselves of a great reward. Performing obligatory acts is more beloved to Allah than voluntary acts. Fajr prayer is an obligation, and performing it in congregation is equivalent to worshiping for the entire night. So how can someone neglect it while striving for voluntary prayers?!
Does sacrificing one sheep avail for the entire household?
Praise be to Allah, and peace and blessings be upon our master, the Messenger of Allah.
In Islamic jurisprudence, the sacrifice (Udhiyah) is considered a Communal Sunnah (Sunnah Kifayah) for the members of a single household who share the same financial support.
If one member of the household performs the sacrifice—even if they are not the primary breadwinner, such as the wife or one of the children—the religious request is fulfilled on behalf of the entire household. This is similar to the Funeral Prayer (Salat al-Janazah), where the obligation is dropped for the community if some perform it.
While the communal request is satisfied by one person's action, the specific spiritual reward (Thawab) for the act of worship belongs only to the person who sacrificed, unless that individual explicitly intends to include the other family members in the reward.
A single sacrifice also avails for a man who is married to more than one wife. And Allah the Almighty knows best.
Does the fast become invalid if water from rinsing the mouth reaches the stomach while performing ablution?
If water reaches the stomach without the fasting person exceeding normal rinsing or being excessive, their fast remains valid.
However, if they exceed the normal practice or exaggerate in rinsing, causing water to enter the stomach, their fast is invalid.
This is because excessiveness in rinsing is prohibited for a fasting person, as the Prophetﷺ said: "Exaggerate inhaling water during ablution, except when you are fasting." [Narrated by the Four Imams]
Transgression (Ta‘addi) refers to rinsing the mouth more than three times, while exaggeration (Mubalaghah) includes gargling, drawing water deep into the nasal passages, or filling the mouth with water in an unusual manner.