Is it permissible to take a portion of the merchandise and receive the remaining amount in cash when taking a Murabaha loan from an Islamic bank to purchase merchandise (clothes)?

If you bought goods from the bank after it had acquired them, then you acquired them yourself, and then you returned some of them to the institution in exchange for money, this is permissible. The institution can reclaim the garments, whether there was a prior agreement or not, because it is a promise to purchase and not a binding contract. What is prohibited is selling goods before acquiring them. Acquisition (possession) occurs by taking what can be taken by hand, by clearance for real estate, and by transfer for what is customarily transferred. However, if the merchant gave you money and kept the garments without you acquiring them, it appears that this is invalid, and you must return the amount and take the garments, then a contract can be made for them.