What is the ruling on eating or drinking forgetfully during the day in Ramadan or during voluntary fasting?
Whoever eats or drinks forgetfully while fasting, whether in an obligatory or voluntary fast, should continue their fast, for it is Allah who has provided them with food and drink. There is no difference between obligatory and voluntary fasting in this ruling.
What is the ruling of Islamic Law on supplicating with other than the transmitted (Ma'thur) supplications in prayer?
All praise is due to Allah, and peace and blessings be upon our master, the Messenger of Allah.
It is permissible to supplicate (make du'a) during the prayer for anything from the affairs of religion or worldly life, and the prayer is not invalidated by doing so.
Shaykh al-Islam, the Imam an-Nawawi, may Allah have mercy on him, says: "Our madhhab [i.e., the Shafi'i madhhab] holds that it is permissible for a person to supplicate during it [the prayer] with anything that is permissible to supplicate with outside the prayer, from the affairs of religion or worldly life. He may say: 'O Allah, grant me wholesome sustenance, offspring, a house, and a beautiful young wife' — describing her; or: 'O Allah, free so-and-so from prison,' or 'destroy so-and-so,' and other such things — and none of this invalidates his prayer according to us. And this is also the view of Malik, ath-Thawri, Abu Thawr, and Ishaq." [Al-Majmu', Vol.3/P.454]. And Allah, the Exalted, knows best.
Is Zakah (obligatory charity) due on leased property, and how is it calculated?
Zakah isn`t due on the leased property itself, but on the saved income from that property if it reached Nissab (minimum amount liable for Zakah), and a whole lunar year had lapsed over saving it.
What is the Islamic ruling on the Udhiyah (sacrificial offfering)?
Praise be to Allah, and peace and blessings be upon our Master, the Messenger of Allah.
The Udhiyah (sacrificial offering) is a Confirmed Sunnah (Sunnah Mu’akkadah) for every adult Muslim of sound mind who possesses the financial means, whether they are a resident, a traveler, or a pilgrim (Haj). This is based on the statement of the Prophet ﷺ: 'When the ten days [of Dhu al-Hijjah] begin and one of you desires to offer a sacrifice, let him not touch [cut] anything of his hair or skin' [Narrated by Muslim].
The point of evidence (Wajh al-Dalalah) here is that the Prophet ﷺ linked the sacrifice to the individual's will and desire by saying, 'and one of you desires.' This indicates that it is not obligatory (Wajib); had it been mandatory, he would have simply said, 'let him not touch his hair until he sacrifices' [without making it conditional upon desire].
Furthermore, it is narrated that Abu Bakr and Umar (may Allah be pleased with them both) would sometimes refrain from offering the sacrifice out of fear that people might mistakenly view it as an obligatory duty [Narrated by al-Bayhaqi and others with a good (Hasan) chain of transmission]. And Allah the Exalted knows best.