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 on waiving a debt owed by a debtor and counting it toward zakāh?
All praise is due to Allah, and peace and blessings be upon our master, the Messenger of Allah ﷺ.
Waiving a debt owed by a debtor, with the intention of counting it toward zakāh, does not fulfill the zakāh obligation. Rather, it constitutes an ordinary act of charity, for which Allah rewards the giver generously — since one of the conditions for the validity of zakāh is that the person paying it must form the intention of zakāh at the actual moment the wealth is paid out. In this case, the debt has already been established as a standing obligation upon the borrower, so it is not valid to simply redirect the intention toward zakāh after the fact.
It is preferable, instead, for the creditor to first collect the debt from the debtor, and then return to him the amount of money he is required to pay as zakāh — or a portion of it — if the debtor happens to fall under one of the eight categories that Allah, the Exalted, has commanded be given from zakāh.
It is stated in ‘Umdat as-Sālik, from the books of the Shāfi‘ī school: "If someone gives [money] to a poor person, stipulating that the recipient return it to him in payment of a debt owed to him, or says, 'I am making what you owe me into zakāh, so take it [as such]' — this is not valid. But if he gives it to him with the [unstated] intention that the recipient will use it to repay him, or says, 'Repay what you owe me, so that I may [then separately] give it to you as zakāh,' or the debtor himself says, 'Give it to me, so that I may [then] repay you with it' — this is valid, and there is no binding obligation for the recipient to actually fulfill this [informal understanding]." And Allah, the Exalted, knows best.
Is it enough to say Tasbeeh (Saying Subhaana Rabbiya Al-‘Atheem during Rukoo`, and saying Subhaana Rabbiya Al-A‘laa during Sujood ) once, or twice during Rukoo`(Bowing in prayer) and Sujood (Prostration)?
All perfect praise be to Allah, The Lord of The Worlds Yes, saying Tasbeeh once during Rukoo` and Sujood is enough, provided that the worshiper`s attentiveness of the heart isn`t undermined during each. As regards the recompense, it depends on the number of Tasbeeh. And Allah Knows Best.
When is supplication (du‘a) more likely to be accepted: before or after breaking the fast in Ramadan?
Du‘a is accepted at all times, and this is part of Allah’s mercy and generosity toward His servants.
The Prophet ﷺ said: "No Muslim makes a supplication that does not involve sin or severing family ties except that Allah grants them one of three things: either He grants their supplication immediately, or He stores it for them in the Hereafter, or He averts from them an equivalent harm." [Narrated by Ahmad]
However, in Ramadan, du‘a is especially likely to be accepted shortly before breaking the fast.
The Prophet ﷺ said: "Three supplications are never rejected: the supplication of a fasting person until they break their fast, the supplication of a just leader, and the supplication of an oppressed person. Allah raises it above the clouds, opens the gates of heaven for it, and says: ‘By My might, I will surely grant you victory, even if after a while.’" [Narrated by Al-Tirmidhi]