Lets look at the logic that why icons are used the first place. Icons make use of our "scanning" ability which is quicker than "reading".
If you put Text First then you are putting less efficient way to learn first and more efficient way later. Doesn't make sense.
Steve Krug in his book "Don't make me think" almost killed himself advocating not to use text where it is not required. If you think your icons are clear enough, you probebly don't need Text Labels to clarify them.
Lets learn some from bootstrap if we could, they are using small (16x16) icons which are complimented by Text labels after the icons. So in their approach scanning element (icon) is small and reading element (text) has increased visibility. It is kind of 50/50 blend of both approaches in which icon is available for you to "scan" and text if you want to "read" even though icon lies first and text later. But in this situation, I have almost always found myself "reading the text" instead of looking at the icons which are slightly difficult to spot and scan because of smaller size.