Is the son of the sister by breastfeeding considered a mahram in Islam, and is it permissible for a woman to go for Hajj with him?
Everything that is prohibited by lineage is also prohibited by breastfeeding. The son of the sister by breastfeeding is considered a mahram, just like the son of the sister by blood, and it is permissible for him to be her mahram for Hajj and Umrah. And Allah Knows Best.
After buying tires, I made an oath not to buy tires from a person. Afterwards, he offered his entire car for sale. What is the ruling on this?
If you bought the entire car and in order to be on the safe side, you should pay an expiation; feeding 10 poor people and the cost of feeding a person is half a JD. And Allah Knows Best.
Do certain vaginal discharges and incontinence of urine nullify ablution, and should underwear be changed?
A person afflicted with constant impurity due to urinary incontinence and vaginal discharges is obliged to make ablution for every obligatory prayer when its time is due, and after removing Najaasah (impurity), and wearing a clean diaper. He/she is obliged to pray immediately even if the impurity is being released, and he/she is obliged to remake ablution, and the aforementioned for every obligatory prayer.
Is it permissible for a girl to wear colored contact lenses?
All Perfect Praise is due to Allah, The Lord of The Worlds.
Wearing colored contact lenses for medical treatment is permissible, and wearing them as an adornment is also permissible, provided that she isn`t seen while having them on by non-Mahrams. And Alalh Knows Best.