Is it permissible to trim the eyebrows if they become excessively long?
Trimming eyebrows is permissible if they become excessively long, yet; it is reprehensible. And Allah Knows Best.
Does the intention (niyyah) of the principal (muwakkil) suffice for the sacrifice (dhabḥ) of the udhiyyah?
Praise be to Allah, and peace and blessings upon our master, the Messenger of Allah.
If a person appoints an agent (wakīl) to perform the slaughter (dhabḥ) on their behalf, the intention (niyyah) of the principal (the one appointing the agent) suffices, and there is no need for the agent to have this intention himself. In fact, even if the agent is unaware that he is performing the sacrifice on someone's behalf as an udhiyyah (sacrificial offering), this does not affect its validity. And Allah, the Most High, knows best.
What is the ruling of Islamic Law on Making up Prayers Missed before Reaching Puberty?
All praise is due to Allah, and peace and blessings be upon our master, the Messenger of Allah ﷺ.
Among the conditions for accountability for one's actions in the Hereafter is taklīf (religious legal responsibility) — meaning, possessing sound reason and having reached puberty. The signs of puberty are: nocturnal emission, menstruation, or reaching the age of fifteen [lunar years].
Whoever missed prayers before reaching puberty is not obligated to make them up, since taklīf did not yet apply to him at that time. Our master, the Prophet ﷺ, said: "The pen has been lifted from three: from the child until he reaches puberty, from the sleeping person until he wakes, and from the insane person until he regains sanity." [Related by Abū Dāwūd]
The method for making up missed prayers and fasts has already been explained in Fatwa No.
2705, and Fatwa No.
876. And Allah, the Exalted, knows best.
Is it permissible to purchase the Udhiyah on installments?
It is permissible to purchase the sacrificial animal (uḍḥiyyah) on installments or by borrowing its price. However, it is not recommended for the poor to do so, because they are not required to offer a sacrifice, and Allah does not burden a soul beyond its capacity. If doing so would lead to negligence in providing for one's dependents (nafaqah wājibah), then giving precedence to obligatory maintenance over borrowing to buy the sacrifice is appropriate. This is based on the saying of the Prophet (peace and blessings be upon him): "It is sufficient sin for a person to withhold food from those whom he is responsible to support."
Furthermore, the sacrifice is valid from one who has a debt, but it is preferable (awlā) to repay the debt first, especially if the debt is due immediately (ḥāll). And Allah Almighty knows best.