Hello! 
It seems you’re thinking of AN 11.12. I’d say there are two main ways to interpret this.
First, the Buddha lists the five spiritual faculties or powers without explicitly calling them that. He tells Mahānāma that those with faith, energy, mindfulness, samādhi, and wisdom succeed. Then, he tells Mahānāma to recollect the Buddha, Dhamma, Saṅgha, etc. based on those faculties.
The first thing to note is that the five faculties in the suttas often refer specifically to faculties of noble ones, or people who are at least stream-enterers or on the path to stream-entry. This is explained in various ways at SN 48, the chapter on the faculties. For example, the faculty of faith (saddhā) mentioned also in the Mahānāma Sutta, is defined as the confirmed faith of a noble one. Likewise, the faculty of wisdom (paññā) is defined as the wisdom of a noble one.
So one way of interpreting the sutta is similar to what we see in a sutta like MN 7. There, the Buddha says that someone who is a noble one should then use their confirmed faith to contemplate the Buddha, etc. and gain samādhi so that they can further their practice and reach arahantship.
This first interpretation is actually directly confirmed by the sutta right before, which is sutta AN 11.11. It’s the first sutta with Mahānāma, followed by the second mentioned above. There, the first sutta is almost identical, but it explicitly says that the person doing the recollections there has “entered the stream of Dhamma.” So it fits the practice taught in MN 7 and some more limited definitions of the faculties at SN 48.
A second interpretation of the passage, if we wanted to make it a bit more accessible and relevant to everyone, would be to look at the differences between AN 11.11 and AN 11.12.
Like I said, the two suttas are almost line-by-line identical, except the line about stream-enterers. AN 11.12 changes that line to say:
“You should develop this recollection of the Buddha while walking, standing, sitting, lying down, while working, and while at home with your children.”
Obviously, this seems much more inclusive. It might even be the case that the second sutta was intentionally meant to show that non-noble ones could also apply the same teaching to their life. This isn’t necessarily the case, as it still says to recollect the Buddha “grounded on” the five faculties, which like I said could easily intend someone who has become a noble one.
But obviously in order to become a noble one, you have to develop the five faculties beforehand. SN 48.50 for example explains how someone uses faith to apply energy to then become mindful to gain samādhi until they gain noble wisdom. Then they continue developing the five faculties once they have secured them for certain.
So you could just take it that the Buddha is saying: in order to successfully practice the recollections in the way mentioned there, where it relies on firm faith leading to inspiration and joy and actual samādhi, you should develop the five faculties to the extent that you can and use them to develop the recollections.
That doesn’t necessarily meaning having samādhi before recollecting the Buddha, in this sense, because recollecting the Buddha is a way of developing samādhi. But you would be developing samādhi, along with the other faculties, and using them to further that practice to bring it to fulfillment.
To summarize, you can take the teaching as applying in two ways. One, that noble ones with the five faculties firmly secured use faithful recollections to gain inspiration for samādhi. Two, that some preliminary development of the five faculties, using them as the framework, is the basis for developing the recollections.
Hope that’s helpful 
