The quoted text puts Einstein's sentence into the context of discussing whether a certain moral can be derived from science. Is science descriptive or prescriptive (= normative)? The text advances the position that science is not normative.
Today this position is shared by all scientists and philosophers of science. Broadly speaking, science investigates what is, but does not prescribe what should be. It was already David Hume who emphasizes that there is no path from facts to norms, see his "is-ought" problem.
Concerning the context of Einstein's quote:
In a discussion on science and religion in Berlin in 1930, he [Einstein] said that our human sense of beauty and our religious instinct are "tributary forms in helping the reasoning faculty towards its highest achievements. You are right in speaking of the moral foundations of science, but you cannot turn round and speak of the scientific foundations of morality." He proceeded to point out that science cannot form a base for morality: "every attempt to reduce ethics to scientific formulae must fail."
but you cannot turn round and speak of the scientific foundations of morality
expresses the same thought as above: One cannot base ethics on science.
You are right in speaking of the moral foundations of science
Einstein possibly means:
Also science has its moral, e.g., to be honest. Do not forge the observed results.
The scientist has a certain moral responsibility concerning development and application of scientific results. Note that it was just Einstein who later advocated the development of atomic bombs in USA, see his letter to Roosevelt.
But I consider the context to restricted to derive what really was Einstein's point.