The father, who cannot be named for legal reasons, gave his young daughter’s mobile phone number to a 26-year-old man.
He then hosted a ‘wedding ceremony’ for them at his house in New South Wales, Australia.
Apparently the father then instructed his daughter that neither she nor her partner were allowed to use contraception.
He went on to set up a ‘special marriage bed’ for the 12-year-old and her adult husband at his home, where they allegedly had sex.
The following morning, he asked his daughter if she needed to shower before prayers, in line with Islamic practice after sexual intercourse, the jury at Downing Centre District Court heard.
Crown prosecutor Siobhan Herbert said: "By her getting married he was stopping the sin of extramarital sex.
"His actions brought about or caused the unlawful sexual activity.”
The father has been charged with procuring a child aged under 14 for unlawful sexual activity.
His trial continues.