Is it permissible for me to deduct the profit from selling the machine from the account when entering into a partnership with my friend, after agreeing to sell it to him, or should I keep the profit from the machine for myself?

Scholars have differed regarding the ruling on a partnership where the capital of one partner is an asset and the other is cash, or where the capital of both is assets. The majority of scholars hold it to be invalid, while Ahmad, in one of the narrations from him, permitted partnership with assets, provided their value is assessed at the time of the contract and considered as capital.

Based on Ahmad's opinion, if you both agree to appraise the machinery and ascertain its value at the time of the contract, the partnership is valid. Upon its termination, each partner takes back the capital he contributed, and the profit or loss is divided between you according to the agreement. However, if the two partners agree that one contributes with his money and the other with his machinery, and each retains ownership of his capital, then this is an invalid contract. There is no problem if the agreement is that you enter the partnership with cash, and then the partnership buys the machinery from you. The profit from the machinery will revert to you according to your agreement.