Regarding profit earned because of reference

Question

Asslam o alaikum,
Respected Mufti Sahab,
By profession I am a doctor, one of my friend recently opened a pathology and asked me to refer patient for any pathological test. He said he would be returning favour as monetary benefit for me. I never push any of my patients to go to his pathology as such, but I do use his writing pad as a part of his advertisement and indirectly refer them to his pathology. But not all patients would go to him, and I don't take any monetary benefit for any other pathology as I don't have any understanding or contract with them. My contract is only with my friend and I help him indirectly by writing prescription on a letter and with his pathology adverts. My question is, will this be considered halal, as I feel quite confused about the salary received from him. 
Please treat this as URGENT.
Thanks

Shariah Board of America · Accepted Answer

بسم اللہ الرحمن الرحیم
Labs have the capacity to pay commission to doctors. But for this, the following issues must be taken into consideration:
1. The patient should not be deceived in the course of treatment or test.
2. Patient should not be forced to take tests from the same lab.
3. The patient should not be prescribed tests unnecessarily and in excess of real medical needs.
4. Unless the understanding and experience of the physician suggests that It would be more beneficial to send tests to that lab, otherwise it would be considered as betrayal.
5. The commission should be fixed in the form of a percentage or a fixed amount, which should not later lead to disputes between the parties.
6. The transaction and setting up commission should be done by mutual consent and there should be no coercion or pressure of any kind.
عن حماد أنہ کان یکرہ أجر السمسار إلا بأجر معلوم۔ (المصنف لابن ابي شیبۃ: : ۲۲۰۵۷ 
عن أبي ہریرۃ رضي اللّٰہ عنہ أن رسول اللّٰہ صلی اللّٰہ علیہ وسلم قال: &hellip; من غشنا فلیس منا۔ (صحیح مسلم: ۱۰۱
Fatawa ID: 1385