No. You can access your purchased downloads at any time from your "My Downloads" area, so you don't have to download your purchase right away or all in one go. This is especially handy for large packages like a commentary or the Entire Bible (which is over 20GB). You can just download what you need, when you need it.
You also have unlimited download attempts, so if you lose your files, your whole system crashes, you can just download your files again.