It is essential to acquire and take possession of items before selling them
Question

I wanted to buy some electric items for my house in which my children and I live. I had no cash, so I went to someone who has cash, and he said: I will buy them for you. So he bought them for 7540 riyals, and sold them to me for 9400 riyals, to be paid in monthly instalments, one thousand riyals every month. What is the Islamic ruling on that?
Praise be to Allah.If he acquires the goods and takes possession of them, then sells them to you after that for a known amount to be paid in instalments, there is nothing wrong with that. But he does not have the right to sell them to you before he takes possession of them. If he knows that you want them and that you need them, then he buys them and acquires them and takes them to his house or the marketplace, then sells these appliances to you for a known price to be paid in monthly instalments, there is nothing wrong with that. End quote.
Shaykh ‘Abd al-‘Aziz ibn Baz (may Allah have mercy on him).
Fatawa Nur ‘ala ad-Darb (3/1450).