The number 7 seems to appear numerous times in Islamic text. This recent realisation has made this association extremely fascinating.. 

1- 7 circumambulation (Ta’waf) around the Kaa’bah during Hajj

2- 7 walks (back and forth) between Al-Safa and Al-Marwah

3- 7 heavens

4- When the Prophet (peace be upon him) was taken to heaven during Miraj he reported to have seen an angel with 70 000 heads, each head having 70 000 mouths, each mouth having 70 000 tongues and each tongue speaking 70 000 languages; all involved in reciting the praises of Allah Almighty (can't remember the reference for this)

5- 7 pebbles to be used each time for stoning of the Jamarat’

6- 70 000 angels write good deeds for one who recites durood shareef

7- The Prophet (peace be upon him) said, ‘Verily! 70,000 or 700,000 of my followers will enter Paradise altogether; so that the first and the last amongst them will enter at the same time, and their faces will be glittering like the bright full moon.’ (Bukhari)

8- 7 days of the week (refers to all religions)

9- 7th day for ‘Aqeeqa’ of a newborn baby

10- 7 bones on which prostration must be done (Sahih) 

11- 7 continents and oceans in the world

12- 70 000 Angels will protect you when you recite Ayat-ul-Kursi while leaving your house

13- Reciting Ayat-ul-Kursi after Wudhu raises you 70 times in Allah Almighty’s rank

14- 7 under Allah Almighty's shade

I might have missed some out. Interesting nonetheless...