The politician hailing from North Rhine-Westphalia did not recite the explicit satirical poem to support its author, comedian Jan Boehmermann, but rather to show that the text was insulting and lacked satirical merit.
"A person's honor is under attack here and the justice must decide if these statements are still covered by freedom of expression and press," Seif told fellow MPs, adding that he was not trying to defend Erdogan.
"Keep in mind that we are in the German parliament, and that even with quotations one should not forget this fact," Edelgard Bulmahn, a cive president of the Bundestag, told Seif.
The speech was broadcast live on national TV. The comedian uploaded Seif's speech to YouTube, turning the politician into an internet sensation. The footage has already been viewed more than 270,000 times.
The notorious poem has been at the heart of a diplomatic scandal between Germany and Turkey that has sparked an intense debate on the state of the freedom of speech in both countries.
Angela Merkel gave the green light to the proceedings against the comedian, much to public discontent. She now wants to repeal the law.
If found guilty, Boehmermann could spend up to three years in prison.