Quarterback Dak Prescott hasn't been a Dallas Cowboy for a full week and already he's gone through two different jersey numbers.

Originally set to wear No. 10 in Dallas, Prescott earlier this week changed to No. 4.

Now we know a little more detail behind how he picked the new number. DallasCowboys.com writer David Helman explains that the new number honors Prescott's mother.

Dak Prescott changed his jersey number to 4 because his mother's birthday is Sept. 4. Mystery explained. — David Helman (@HelmanDC) May 5, 2016

Can't see the tweet on mobile? Click here.

Prescott's mother died in the middle of the 2013 season after a year-long bout with colon cancer.

His mother, Peggy, was very close to Dak. He spoke about her fondly last August in an interview with ESPN.

The No. 4 has previously been worn only by punters and kickers in Dallas, most notably Mike Saxon and Shaun Suisham.

Find out jersey numbers for all the Cowboys' draft picks.