Is an oath considered binding if a person says "By Allah, I will" and does not complete the statement?

Whoever says "By Allah" and then stops, his oath is not binding because he has not sworn concerning anything. The oath that necessitates expiation is either an oath of truthfulness (e.g., "By Allah, I will not do such and such") or an oath of breaking (e.g., "By Allah, I will certainly do such and such").