Musahiplik or Müsahiplik (roughly, "Companionship / Spiritual brotherhood") is a covenant relationship between two men of the same age, preferably along with their wives.
In a ceremony in the presence of a dede the partners make a lifelong commitment to care for the spiritual, emotional, and physical needs of each other and their children.
After the Hijra, the Islamic prophet Muhammad instituted brotherhood between the emigrants, Muhajirun, and the helpers, Ansar, and he chose Ali as his own brother.
The ties between couples who have made this commitment is at least as strong as it is for blood relatives, so much so that müsahiplik is often called spiritual brotherhood (manevi kardeşlik).
[2] Krisztina Kehl-Bodrogi reports that the Tahtacı identify musahiplik with the first gate (şeriat), since they regard it as a precondition for the second (tarikat).