Mathew Knowles Congratulates Beyonce on the Arrival of Her Twins

Beyonce's 65-year-old father is a granddad again!

The twins are here!

Beyonce​'s father Mathew Knowles took to Twitter and Instagram on Sunday morning to congratulate his daughter on her new bundles of joy.

WATCH: Beyonce Reportedly Gives Birth to Twins!

“They're here! #beyonce #twins #jayz #happybirthday,” he shared. The post also contained a photo “Happy Birthday to the wins! Love, Granddad.”

Beyonce and Jay Z welcomed their twins ​this week, according to multiple reports. The 35-year-old singer​, who is already mom​ to​ 5-year-old​ Blue Ivy Carter, famously announced ​she was expecting twins ​with a floral maternity pic ​on ​Instagram in February.

Though Knowles is grandfather to the twins, the 65-year-old found out about Beyonce’s pregnancy via social media just like the rest of the world. The “Formation” singer’s father said he was “shocked” but “happy” to find out she was expecting.

"That was very smart that she did it rather than someone else, [like] the media, doing it. So I think that was a really smart move on her part," he said at the time, adding that he thinks "it was strategy" and that "there's more to come."

ET has reached out to reps for Beyonce and Jay Z for comment.

See more on Beyonce’s pregnancy in the video below.