The drama aired on BBC One on Sunday night and fans have been raving online.
There was heavy praise for the latest one liner from Superintendent Hastings, played by Adrian Dunbar.
During an interrogation scene, he said: ‘Jesus, Mary, Joseph and the wee donkey.’
Following the episode, fans shared their appreciation for the line.
One tweeted: ‘Best line yet.’
Another wrote: Thought that was the best line Ted has come up with yet… brilliant.’
One said: ‘Bet no one had that on their bingo card.’
While another went one step further and declared it: ‘Best line in the history of television.’
One wrote: ‘What a great line....that will go down in TV history.’
The episode, which is the penultimate one in the sixth season of the BBC drama, became the show’s most-watched episode ever.
It was viewed by an average of 11 million viewers and 51.7 per cent of the audience share, according to the broadcaster.
The finale of the sixth season will air next Sunday.