Thank you for your question. Since you are currently enrolled in the doctorate program at Effat University and your research is being conducted under the supervision of professors there, you should mention Effat University as your primary and official affiliation at this stage.

Even though you work at Dar Al-Hekma University and plan to carry out future research there, unless that institution is directly involved in your current doctoral research (e.g., co-supervision, joint funding, or institutional support), it is better not to list it as an academic affiliation for now.

To avoid any academic or administrative complications, especially related to full-time enrollment, supervision, or university policies, it’s recommended to acknowledge only Effat University until you complete your PhD or until both universities formally collaborate in your research.

Your primary affiliation is to your home university, while you should also add the university where you do your doctorate as the second affiliation. Both should be mentioned.

Your affiliation (can be a permanent or temporary relation/connection) with an organization (in your case). There is no harm in indicating your affiliations to various institutions/organizations, BUT the type of relationship should come out clearly in order to mitigate against any confusion.