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.
When is Istikharah (guidance prayer) Du`a offered, before Tasleem (saying asalamu alikum warahmatu allah wa barakatuh to end the prayer), or after it?
It is offered after Tasleem.
What is the expiation for perjury?
One who commits perjury should repent, seek Allah`s forgiveness and offer an expiation which is: feeding ten indigent persons, or clothing them, or giving a slave his freedom, but if that is beyond his means then, he should fast for three days. Allah, The Almighty, Says in this regard (What means): "Allah will not call you to account for what is futile in your oaths, but He will call you to account for your deliberate oaths: for expiation, feed ten indigent persons, on a scale of the average for the food of your families; or clothe them; or give a slave his freedom. If that is beyond your means, fast for three days. That is the expiation for the oaths ye have sworn. But keep to your oaths. Thus doth Allah make clear to you His signs, that ye may be grateful." [Al-Ma`idah/89].
What is the ruling of Islamic Law on a father shaking hands with his son’s wife after she has been divorced three times?
All praise is due to Allah, and peace and blessings be upon our master, the Messenger of Allah.
The wife of one’s son is among the women permanently prohibited to the husband’s father as soon as the marriage contract is concluded, based on the saying of Allah the Exalted: “Prohibited to you are your mothers, your daughters, your sisters, your paternal aunts, your maternal aunts, your brother’s daughters, your sister’s daughters, your foster mothers, your foster sisters, your wives’ mothers, and your stepdaughters under your guardianship [born] of your wives with whom you have consummated marriage. But if you have not consummated marriage with them, there is no sin upon you. [Also prohibited are] the wives of your sons who are from your loins, and that you take [in marriage] two sisters simultaneously, except for what has already occurred. Indeed, Allah is ever Forgiving and Merciful.” [al-Nisāʾ/23]
This prohibition begins once the son’s marriage contract with his wife is complete, and it remains in force even if the son separates from her before consummation or before any seclusion (khalwah) with her. It is therefore permissible for the father to shake her hand and to be alone with her, provided there is no fitnah (temptation) and no suspicion.
It is stated in ʿUmdat al-Sālik (p. 204): “It is forbidden to marry… the wives of one’s fathers and of one’s sons. All of these women become prohibited by the mere contract, … all of that being a permanent prohibition.” End quote, with slight adaptation. And Allah Almighty knows best.