"Adultery is not just determined by the heart or thoughts," said the Pope. "It is also physical as there is a third person involved."
At his weekly sermon on Wednesday, the pope said he will travel to the US next week and stay until 8 August for medical checkups.
Upon his return, the pope will hold the annual "national unity" iftar (fast breaking) on the occasion of the Islamic holy month of Ramadan.
The pope had to cancel theiftar last year due to an illness.
The pope denounced claims that some Copts have changed their religious affiliation as a result of the Coptic Church's intransigence on the issue of a second marriages for Christian divorcees.
"We do not welcome them in church if they do not abide by our religion," he said.
Shenouda added that he has agreed to omit an article on adoption in the new personal status draft law, currently being drafted by the Ministry of Justice for Egypt's non-Muslims, in order to maintain good relations with the Islamic community.
"We want to expedite the issuance of this law," he concluded.
SIC: AlAl