He said that, while the murder conviction left no room for doubt about what had happened at the family home in Handsworth Wood, Birmingham, the prosecution had been unable to say for sure what the motives behind the killing had been.
The court heard Mumtaz, who suffers from a genetic condition which has left him deformed, married his bride in an arranged ceremony in her homeland of Pakistan.
This was 14 months before she died while six months pregnant with their first child.
Birmingham Crown Court heard that a day before her death in the early hours of a July 2009 morning, Mrs Mumtaz, who spoke no English, had sounded stressed when she called her parents to tell them her husband and others in their neighbourhood had been suggesting she may have become pregnant during a solo trip to Pakistan.
But the judge said a less unlikely explanation for what happened was that the defendants believed Naila had been possessed by a jinn - a mischievous spirit mentioned in the Koran - and that they deliberately smothered her in order to get rid of the jinn.
The judge added: "That's not an easy thing for those of us in the West to understand, but the evidence (from the trial) was that a belief in jinns is widespread in the community in which they lived. During the trial, prosecutor Christopher Hotten QC said family members had told police a person had been present at the house praying to get the spirit out of her."
Mumtaz claimed his wife had suffocated herself by putting her hand in her mouth and she tried to strangle herself and that his parents and Hassan, 24, who all lived at the house, were trying to hold Mrs Mumtaz down to stop her from harming herself. Ambulance staff discovered Mrs Mumtaz unconscious in a bedroom with bruising to her arms and face. She died shortly after being taken to hospital at around 4.30am.
Prosecutors said that while complex cultural beliefs underpinned the defence case, the defendants had given untruthful accounts.
The court heard Mumtaz suffered from Klippel-Feil Syndrome, a rare genetic disorder which means the neck is shortened. However, it was alleged his bride had willingly entered into the arranged marriage, despite his deformity.
Defence barristers yesterday said that at the most, the defendants were guilty of a desire to cause really serious bodily injury, and not death.
Ul-Haq and Aslam, who the judge said were more likely to have instigated what was done to Naila, were sentenced to a minimum term of 15 years each. Their son and Hassan, who is married to the couple's daughter, were sentenced to a minimum of 14 years.
Hassan was said to have acted like a dutiful son-in-law, who, like Mumtaz, went along with what the couple thought should be done. Mumtaz muttered I loved her as his father guided him out of the dock.
Detective Inspector Simon Astle of West Midlands Police, who investigated the case, described it as tragic and deeply upsetting. He added: "It is unthinkable that those who she was closest to would take her life in the belief she had been possessed by evil spirits."
In a statement, Mrs Mumtazs family said their loved one was a happy, confident and beautiful young woman.
They hoped the case would help raise awareness of the issues faced by Naila and young people like her, adding: "We need to empower people who are vulnerable and isolated to seek help in these circumstances."
