Victoria Beckham, also known to many as Posh Spice, and her husband David Beckham welcomed their first daughter, Harper Seven Beckham, Sunday. The baby girl is the Beckhams' fourth child, after Brooklyn, 12, Romeo, 8, and Cruz, 6.

All of Victoria and David Beckham's children have strange names, but the announcement of Harper Seven has confounded many.

Harper is an old English name that [Victoria] has always liked, a source close to the Beckhams told magazine Us Weekly.

Seven is a very spiritual lucky number. She was born in the seventh month, in the seventh hour, the friend continued.

Before the interview, many were speculating that the Beckham's were fans of Harper Lee's To Kill a Mockindbird. Other suggested classic TV sit-com Seinfeld, in which George Costanza famously wants to name his first born child - be it boy or girl - Seven.

The name spurred Jason Alexander, the actor who played George, to tweet: Alright, I cannot hide the truth - Harper Seven Beckham is the love child of me and David Beckham. (I told you people would know, David).

Beckham has also worn the number 7 for the English national team, although soccer numbers aren't as permanent in an athlete's career as in basketball or football. Beckham has also worn the number 10 jersey, which is generally reserved for a team's best midfield or attack player. The international star also wears 23 for his US club team, LA Galaxy.

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