What is the expiation for intentionally breaking the fast in Ramadan due to milk from a woman's breast entering the mouth?

Swallowing milk intentionally during a Ramadan day from a woman's breast invalidates the fast and necessitates sin, making up the fast, repentance, and seeking forgiveness. As for whether a major expiation is required or only making up the fast, scholars have differed on this matter, holding two opinions. The more preponderant view is that it only necessitates making up the fast along with repentance, and this is the opinion of most scholars.