Is it permissible to listen to chants praising the Prophet if accompanied by musical instruments?
If singing, or chanting in praise of the Prophet was accompanied by a forbidden musical instrument, then it is forbidden.
There is a car dealership, and their method of selling is as follows: The customer pays the full price of the car, the car is registered in their name, and another contract is written in which the company commits to refunding the full price of the car to the customer after one year from the purchase date. What is the Islamic ruling on this transaction?
As for purchasing the car, paying its price, and owning it, this is a valid sale with no issue. However, the condition of refunding the price — whether the car is returned to the seller or not — is an invalid condition that nullifies the entire contract. Therefore, this transaction is invalid and not permissible. And Allah Knows Best.
Is Zakah (obligatory charity) due on the Zakah money received by a poor person, and reached a Nissab (minimum amount liable for Zakah), and a whole lunar year had lapsed over having it in his possession?
Yes, the poor who possessed a Nissab for a whole lunar year is obliged to pay the Zakah due on that money even if it was given to him as a Zakah money in the first place. And Allah Knows Best.
Is prayer nullified by having thoughts while performing it?
Prayer isn`t nullified by having thoughts while performing it, provided that the praying person offers all of its pillars and meets all of its conditions. However, the reward decreases significantly in the absence of reverence since a praying person is rewarded according to the attentiveness of his/her heart during prayer.
